Entry Type ID Date Applicable Rating System Primary Credit Inquiry (LIs) Ruling (LIs) Related Addenda/LIs Related Resources Campus Applicable Internationally Applicable Country Applicability Reference Guide (Addenda) Page (Addenda) Location (Addenda) Description of Change (Addenda) "LEED Interpretation" "10020" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Is it acceptable for a project to utilize a campus solar farm to achieve points under EAc2, and at the same time utilize rooftop solar panels, tied directly into the building power system, to achieve points under EAc1?" "The solar farm can count towards EAc2, while the solar panels can count towards EAc1, and in fact, the PV generated on the building could be counted towards both EAc1 and EAc2 points. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10021" "2011-05-09" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "For a building renovation where building employees participate in flexible working arrangements, resulting in a significant decrease in building energy and transportation costs per employee, is it acceptable to use the current building size, plus the expansion that would have been necessary to accommodate all existing plus new employees working from the building, as the baseline building case?" "ASHRAE 90.1-2004 Appendix G requires, under Table 3.1, that the equivalent dimensions for the proposed and baseline envelope, including roof, exterior wall, doors and perimeter area, shall be the same in both models. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10022" "2011-05-09" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "For a Distribution Center, is it acceptable to distribute lighting in a manner that takes into account shelve placement, eliminating unnecessary energy consumption illuminating the shelves\' tops?" " Yes, design teams are encouraged to develop integrated lighting designs that improve efficiency while meeting the design intent of the owner. Strategic placement of lighting fixtures is an appropriate strategy for accomplishing improved lighting efficiency. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10023" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "If an area adopts ASHRAE 90.1-2007 as its energy code, is it acceptable to still use ASHRAE 90.1-2004 for the baseline model, even though such a building would no longer meet code in the area?" "The rating system language for EA Credit 1 specifically references ASHRAE 90.1-2004 Appendix G (without addenda) as the basis for documenting credit performance under Option 1. As such, there is no requirement for project teams to use ASHRAE 90.1-2007 to document compliance even if their local jurisdiction requires compliance with ASHRAE 90.1-2007. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10024" "2011-05-09" "New Construction" "EAc1: Optimize Energy Performance" "For a major renovation to an existing office building, where a data center will be relocated from the existing space to the new space and provided with a dedicated electrical and HVAC system, is it possible to remove the data center from the energy simulation, similar to the exclusion permitted in EBOM EAc1?" "The data center can be excluded provided that it has a dedicated HVAC system, all utilities are separately metered, all common surfaces between the data center and office space are treated with additional insulation, and the employees of the data center are excluded from FTE counts. Everything within the LEED Project Boundary must be included in the energy model.\n\n **Update October 1, 2013: Exclusion of any part of the project building, no matter how it is separated, is not acceptable. Everything within the LEED Project Boundary must be included in the energy model." "None" "None" "X" "LEED Interpretation" "10025" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Per ASHRAE 90.1 Appendix G, in order to model an addition excluding the existing building, the HVAC system must be completely separate. Is it acceptable to model the addition separately if it shares steam to hot water heat exchangers with the existing building, but the air handling system is completely independent?" "It is acceptable to model the addition separately. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10026" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Is it acceptable to use research on potential efficiencies of data center equipment, as published in an ASHRAE Journal article, to demonstrate the difference between baseline and design performance of a data center?" "The performance metrics in the article itself are based on models generated by authors to demonstrate ""order of magnitude savings possible"" and do not provide any confidence in the effectiveness of the measures listed. Efficiencies and energy savings should come from manufacturers\' documentation. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10027" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "For a building with two tenants, only one of whom is currently building out the space, is it necessary to include the space to be occupied by the future tenant within the project boundary?" "Because the tenant space comprises less than 50% of the total building area, the project should pursue certification under LEED for New Construction and include the tenant space in the credit calculations. For unfinished tenant spaces, tenant guidelines must be provided. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10091" "2011-08-01" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a new industrial building in Suzhou, China. The project consists of 8,000 2 of office area and 49,587m2 of production area. The production area includes welding machines, cranes, assembly and painting machines. The electricity required by the process machines represents approximately 60% of total energy cost. According to LEED NC 2.2 Reference Guide, project teams may follow the Exceptional Calculation Method to document measures that reduce process loads. Pursuant to EAc1 CIR posted on 9 May, 2008, the process loads would be firstly modeled identically in the Baseline and Design Cases, using ASHRAE 90.1-2004 Appendix G Performance Rating Method, and then the manufacturing portion will be modified in a proposed Exceptional Calculation Method. Those two energy saving results will be combined to fill out the EAc1 Submittal Template and come up with overall cost savings for the whole project. The CIR is looking for verification on the methodology used in Exceptional Calculation to calculate the process loads of baseline and design cases Process Baseline Case: The welder machine A in the baseline is a standard welding machine in this industry and is widely used. Welder A is very reliable and last more than 20 years. The project owner has purchased hundreds of welder A and has used them in most of global factories, including Cat Peoria, Ill., Cat Decatur, Ill., Cat Aurora, Ill., Cat Joliet, Ill., Cat Atlanta, Georgia, Cat Minneapolis, Minnesota, Cat UK - Peterlee, Cat Work Tools, Kansas, Cat Mexico, Monterrey, Cat Brazil - Piracicaba, Cat China - Xuzhou, etc. The performance of welder A will be evaluated based on factory testing. Process Design Case: A brand new welder named welder B will be applied in design case, which is capable of saving considerable amounts of input powers. The machine was designed from the ground up for our client\'s specific application, so the market penetration now is zero. Welder B was tested exactly in the same way as Welder A. The testing result shows that the idle watts and arch input power of Power+ are all lower than welder A. Calculation: Given the same local electricity utility rate and same operation schedule (12 hours of arc hours and 12 hours of idle hours per day, 250 working days per year), the difference between annual electricity consumptions of welder A and B would be the process energy saving. Credit Interpretation Request: Please confirm that our assumptions and methods for calculating the process energy load for baseline and design case are acceptable for EAc1." "The description of the method for calculating and determining process energy savings appears reasonable. To be consistent with previous credit interpretation rulings, the submission documentation would need to follow guidance from EAc1 CIR ruling dated 02/09/2009. Please note, the baseline should be established on the basis of the current industry wide practice and not the project owner's past practices. In addition, note that a maximum of 4 EAc1 energy points can be awarded for process energy savings.\n\n **Update October 1, 2013: Projects are eligible to claim more than 4 points from process energy efficiency savings. This guidance supersedes CIR 2/9/2009 which placed 4 point maximum limit on process energy savings." "None" "None" "X" "LEED Interpretation" "10129" "2011-11-01" "New Construction, Core and Shell, Retail - Commercial Interiors" "EAc1: Optimize Energy Performance" "LEED Core and Shell projects are is allowed to show energy savings associated with tenant improvement measures if documented in the lease agreement. Can anchor tenant leases, were executed well before the start of design, also be used? As a result of timing issues, it is not always practical to include specific energy efficiency measures in the lease agreement. Many of our tenants, especially supermarkets and other anchors, are extremely interested in energy efficiency and include these measures in their build-outs. All of these measures are documented in the tenants\' construction drawings, which are typically completed simultaneously with the core and shell drawings. \nWe desire to be able to include tenant energy efficiency measures that are documented in the tenants\' construction drawings in the LEED for Core and Shell energy model. We would argue that this approach has more certainty and credibility than measures documented in the lease agreement. We would be using measures in permitted, final construction drawings, not requirements that were agreed to during lease negotiations.\nPlease confirm that the LEED for Core and Shell project can include energy efficiency measures documented in the tenant\'s final construction drawings as part of the LEED for Core-and-Shell energy model. " "The energy efficiency measures for tenant spaces documented in the tenant\'s final construction drawings can be used as part of the LEED Core and Shell energy model if the tenant signs a letter confirming that the final construction documents will be implemented as designed; that any modifications to the final construction documents will be evaluated for their impact on energy efficiency; and that the overall efficiency savings contributed by the tenant improvements will be maintained between the final construction documents and the construction phase. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10158" "2012-04-01" "New Construction, Core and Shell, Schools - New Construction, Retail - New Construction, Healthcare, Data centers - New Construction, Hospitality - New Construction, Commercial Interiors, Retail - Commercial Interiors, Neighborhood Development" "EAc1: Optimize Energy Performance" "Can we take credit for a demand ventilation system for an automotive service area?\n\nEssentially we propose to model the service area in the Baseline Cases at 100% outside air at 1.5 CFM/sq.ft. during occupied periods to meet ASHRAE 62.1. We plan to model the service area in the Proposed Case with typical storage ventilation rate. See rationale below to validate our assumptions.\n\nWe further propose to model this energy efficiency measure in the standard credit energy models (not as an exceptional calculation) as part of the Baseline and Proposed Cases in order to accurately account for the differences in ventilation load. The differences are based on outside air conditions which change throughout the year and they also impact the supply air unit and fan sizes. The simulation program must size the equipment for the Baseline Case at the peak load and model it use 8760 hours in the year. \n\nASHRAE 62.1 lists a specific minimum ventilation rate for automotive service areas at 1.5 CFM/sq. ft. Ventilation reduction controls are not stated in Ashrae 62.1, nor are they mandated in ASHRAE 90.1-2007. The governing Mechanical Code (International Mechanical Code) optionally permits the use of approved automatic detection devices to control the required ventilation fans and/or make-up air systems. Large make-up air systems providing 100% outside air are still readily available and utilized in order to meet the mandated code. \n\nWe have utilized the following assumptions for modeling energy usage:\n\nBaseline Case - The exhaust ventilation system is modeled to operate at 1.5 CFM/sq.ft. during occupied hours per occupancy schedule. The modeling software automatically sizes the air conditioning system to operate as a 100% outside air system as the total CFM requirement exceeds the design load amount. The unoccupied fan cycle does not include the ventilation and only operates to maintain unoccupied thermostat set point.\n\nProposed Case - The exhaust ventilation system is modeled to be non-operational at any time. We make this assumption based on calculation and witnessed operation at like facilities with the identical control system in place. We have calculated carbon monoxide production based upon maximum estimated daily vehicle round trips through the service area. Eighteen service stalls with an average of 3 vehicles per day and 1 minute round trip drive time yields an estimated total vehicle drive time in the service area to be 54 minutes. The average modern vehicle with catalytic converter produces approximately 150 CFM of exhaust airflow at idle to slow speed containing approximately 1,000 PPM of carbon monoxide. 150 CFM X (0.1%) = 0.15 CFM of carbon monoxide production. The requirement to engage the exhaust ventilation system is 50 PPM of carbon monoxide. The volume of the space is 236,900 cu.ft. and would require 11.845 cu.ft. of carbon monoxide to engage the system. This would require 78.97 minutes of continuous operation without any dilution in a facility this size which exceeds the estimated maximum vehicle operation time of 54 minutes by 30%. The air conditioning equipment serving the area provides 800 CFM outside air and is equivalent to a complete air change twice a day and therefore doubling the daily total required operation time to 157.94 minutes. Operation of vehicles for diagnostic testing is excluded as there is a separate tailpipe extraction system in place to remove all exhaust during testing. \n\nCalculations are no substitute for actual conditions. We have interviewed service managers as to the operations of the emergency exhaust system controlled with a CO monitor system. The feed back is overwhelming that the emergency system is never engaged during normal operation. The technicians in these facilities have been trained in the control systems operations and do not desire to have their ""conditioned"" air purged from the building due to excessive operation of the vehicles within the space." "A project team cannot be awarded credit for demand controlled ventilation in an automotive service area, due to concerns over contaminants, and possible effects on indoor evironmental quality. As there is no current accepted methodology, the potential human health risks outweigh the energy savings." "None" "None" "LEED Interpretation" "10241" "2012-10-01" "New Construction, Existing Buildings, Core and Shell, Schools - New Construction, Retail - Commercial Interiors, Healthcare" "EAc1: Optimize Energy Performance" "Many projects in Europe are connected to highly efficient district energy systems. However, the EAp2/EAc1 Option 2 guidance provided in the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) document is not well-suited for the complex interconnected district energy systems with multiple fuel sources that are common in Europe. Many European countries already make use of the Primary Energy Factor (PEF) as a means of evaluating district energy performance and building energy performance. Is there an alternative compliance path available to document EAp2/EAc1 credit for the district energy system using the Primary Energy Factor in lieu of the DESv2 Option 2 compliance path?" "An alternative EAp2/EAc1 compliance path is available to document the energy performance for complex interconnected district energy systems in Europe using the Primary Energy Factor and the greenhouse gas emissions associated with these systems. The Sweden Green Building Council developed an approved method, ""Treatment of European District Energy Systems in LEED"" (available November 1, 2012), which may be used in lieu of EAp2 Option 2 of the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" guidance. This compliance path is currently available for projects located in Europe only. The guidance is located at \n \nNote: The ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) is Optional Guidance for LEED 2009 projects. However, project teams that use the guidance must apply all relevant portions of the guidance. The alternative compliance path outlined in the ""Treatment of European District Energy Systems in LEED"" may only be used to replace Option 2 of the EAp2/EAc1 Energy Modeling Path defined in the DES v2 guidance. Project teams that opt to use the ""Treatment of European District Energy Systems in LEED"" method must comply with all other applicable requirements of the DES v2 guidance such as those defined for EA Credit 3, EA Credit 4, EA Credit 5, etc.\n \nApplicable Internationally; only for projects located in the Europe region. " "10239, 10243" "Treatment of Scandinavian District Energy Systems in LEED v1 2012" "X" "LEED Interpretation" "10243" "2012-10-01" "New Construction, Existing Buildings, Core and Shell, Schools - New Construction, Retail - Commercial Interiors, Healthcare" "EAc1.3: Optimize Energy Performance, HVAC" "Many projects in Europe are connected to highly efficient district energy systems. However, the EAp2/EAc1 Option 2 guidance provided in the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) document is not well-suited for the complex interconnected district energy systems with multiple fuel sources that are common in Europe. Many European countries already make use of the Primary Energy Factor (PEF) as a means of evaluating district energy performance and building energy performance. Is there an alternative compliance path available to document EAp2/EAc1 credit for the district energy system using the Primary Energy Factor in lieu of the DESv2 Option 2 compliance path?" "An alternative EAp2/EAc1 compliance path is available to document the energy performance for complex interconnected district energy systems in Europe using the Primary Energy Factor and the greenhouse gas emissions associated with these systems. The Sweden Green Building Council developed an approved method, Treatment of European District Energy Systems in LEED"" (available November 1, 2012), which may be used in lieu of EAp2 Option 2 of the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" guidance. This compliance path is currently available for projects located in Europe only. The guidance is located at \n \nNote: The ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) is Optional Guidance for LEED 2009 projects. However, project teams that use the guidance must apply all relevant portions of the guidance. The alternative compliance path outlined in the ""Treatment of European District Energy Systems in LEED"" may only be used to replace Option 2 of the EAp2/EAc1 Energy Modeling Path defined in the DES v2 guidance. Project teams that opt to use the ""Treatment of European District Energy Systems in LEED"" method must comply with all other applicable requirements of the DES v2 guidance such as those defined for EA Credit 3, EA Credit 4, EA Credit 5, etc.\n \nApplicable Internationally; only for projects located in the Europe region. " "10239, 10241" "Treatment of Scandinavian District Energy Systems in LEED v1 2012" "X" "LEED Interpretation" "1573" "2006-09-19" "New Construction" "EAc1: Optimize Energy Performance" "Purchased chilled water utility rates include energy costs, equipment maintenance costs, water costs (for cooling tower make-up), etc. If a proposed design uses purchased chilled water from a utility (as opposed to on site chillers or some other form of cooling capacity on site), are we required to use the published utility rate that includes all of these costs in our energy model? Or are we allowed to work with the utility to determine which portion of their rate is solely for the energy costs?" "Use of the published utility rate (including all of the constituent costs) is required for the energy model. Per ASHRAE 90.1-2004, Section G2.4 on Energy Rates: ""Annual energy costs shall be determined using either actual rates for purchased energy or state average energy prices published by DOE\'s Energy Information Administration (EIA) for commercial building customers, but rates from different sources may not be mixed in the same project."" There is no exception that allows excluding constituent costs other than energy costs. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1574" "2006-11-03" "New Construction" "EAc1: Optimize Energy Performance" "Exception c from G3.1.1 of ASHRAE 90.1-2004 indicates we should use separate single zone systems conforming with the requirements of System 3 or System 4 in our baseline energy model for any zones having special pressurization requirements. We assume this would include various laboratory and hospital spaces, among others. Can these baseline systems be modeled as constant volume reheat systems? In a humid climate, Systems 3 and 4 would not be suitable for a laboratory with 100% or high outside air percentages unless reheat was allowed. Exception c to section 6.5.2.1 allows simultaneous heating and cooling where there are special pressurization relationships, but the Performance Rating Method of ASHRAE 90.1-2004 does not seem to reference using prescriptive requirements to determine how our baseline model can be set up." "The applicant is requesting an exception to the baseline system modeling as per ASHRAE 90.1-2004 Appendix G Performance Rating Method (PRM). The PRM is not set-up for compliance purposes. It requires you to compare the building design to another building that would typically be built for the size and function of the project. Appendix G must be looked at in its entirety, not in isolation. Therefore, to maintain the integrity of the modeling protocol set forth therein, the system types cannot be switched or manipulated. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1577" "2006-09-19" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1: Optimize Energy Performance" "The project consists of a single story 6,300 sf office building attached to a 160,000 sf manufacturing facility. The issue is how to model the heated only manufacturing area. The requirements from ASHRAE 90.1-2004, Appendix G state, ""all conditioned spaces in the proposed design shall be simulated as being both heated and cooled even if no heating or cooling system is to be installed."" Furthermore, ""where no cooling system exists or no cooling system has been specified, the cooling system shall be identical to the system modeled in the baseline building design."" These ASHRAE 90.1 requirements indicate that the proposed Constant Volume, 100% Outdoor Air, Gas-Fired, Make-Up Air Unit would need to include the baseline Variable Volume, 100% Outdoor Air, Chilled Water, Packaged Rooftop Unit for cooling. Current industry energy modeling software, approved by ASHRAE 90.1, cannot model this system for a single space. It also is unrealistic to compare the proposed Make-Up Air Units to a VAV w/Reheat System in a manufacturing facility. Our design team suggests that any heated only space should be modeled as heated only (no cooling) for the proposed and baseline model. This is mainly because if it were possible to model the ""imaginary"" cooling system for heated only spaces it would provide the project with unwarranted energy credit or debit. Specifically, if the loads were reduced between each simulation, for reasons such as improved insulation, the project could use less electricity and therefore gain energy credit from a cooling system that does not exist. Please advise if our recommended procedure to model ""heated only"" spaces is acceptable, and if not, what is the USGBC\'s recommended method to comply with ASHRAE 90.1-2004 requirements in this instance?" "The proposed modeling procedure does not comply with the requirements of ASHRAE 90.1-2004, Appendix G, which is the referenced standard for the purpose of the credit. Table G3.1, #10(d) states clearly: ""(d) Where no cooling system exists or no cooling system has been specified, the cooling system shall be identical to the system modeled in the baseline building design."" There isn\'t sufficient information about the design HVAC system provided in the request, to identify the correct baseline system configuration. If indeed there is no simulation tool that is capable of modeling the systems, the Exceptional Calculation Method (Section G2.5, Appendix G) should be employed. Table G3.1, # 13. Modeling Limitations to the Simulation Program states clearly ""If the simulation program cannot model a component or system included in the proposed design explicitly, substitute a thermodynamically similar component model that can approximate the expected performance of the component that cannot be modeled explicitly."" Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1580" "2006-10-03" "New Construction" "EAc1: Optimize Energy Performance" "Our project is registered under LEED version 2.1 and is located in California. Its energy simulation for code compliance demonstrates energy savings relative to Title 24 2005. LEED 2.1 Energy and Atmosphere Credit 1 Table 8c Point Interpolation Table converts Title 24 2001 savings to EAc1 points, but there is no equivalent table for Title 24 2005. Several studies have shown that Title 24 2005 is significantly more stringent than Title 24 2001 (See, for example, 2005 Title 24 Savings by Design Impact Study, Energy Soft LLC, which shows that project savings calculated relative to Title 24 2005 are 10-20% less than when calculated relative to Title 24 2001. This study is available at http://www.californiaenergyefficiency.com/efficiency/SCGWorkpapers/NonPartnershipPrograms/SavingsByDesign/SavingsByDesignWorkpapers.doc.). Using the cited study above, can we assume that the Title 24 2005 version is 10% more stringent than Title 24 2001, add 10% to our project\'s savings calculated relative to Title 24 2005 and assign EAc1 points based on Table 8c? As a fall back, acknowledging that Title 24 2005 is at least as stringent as Title 24 2001, may we use Interpolation Table 8c with our simulated savings (as is) relative to Title 24 2005 so that we may avoid re-modeling the project for Title 24-2001?" "California Title 24-2005 code can be used in lieu of California Title 24-2001 code in the form of direct equivalence; no extra savings can be assumed in LEED. You may apply your Title 24 modeling results as-is to Table 8c in the point interpolation document found on www.usgbc.org/leed/nc. Please note another option: the USGBC allows the application of California Title 24-2005 for LEED-NC v2.1 projects if the NCv2.2 compliance path is adopted as a suite of credits including EAp2, EAc2 and EAc6. Please refer to www.usgbc.org/leed/nc, Version 2.1 section, for the document ""Submitting v2.2 credit paths"" for more information. ""California Title 24-2005 Equivalency,"" within the Version 2.2 Rating System section of that Web page, may also be useful." "None" "None" "LEED Interpretation" "1581" "2006-10-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Title-24 vs. ASHRAE 90.1 for LEED-NCv2.2 EA Credit 1: LEED has stated that it will accept Title 24-2005 as an equivalent replacement for the ASHRAE 90.1-2004 code for the EA credit 1. LEED 2.2 requires the total energy use of the building (regulated and process loads) be used in the energy savings calculation for EA1. Title 24-2005 uses only regulated loads in the energy calculation. Since LEED 2.2 accepts Title 24-2005 as an ASHRAE 90.1-2004 equivalent, do the process loads need to be included in the Title 24 model for the LEED 2.2 EA credit 1 calculation? Or is the standard Title 24 analysis that considers only regulated loads the appropriate comparison?" "Process loads must be included in the Title 24 model for the LEED 2.2 EAc1 compliance. LEED NC v2.2 EAc1 requires that the ""default process energy cost is 25% of the total energy cost for the baseline building"". Since the Performance Rating Method in Appendix G of ASHRAE 90.1-2004 also considers total energy (regulated and process), it is only appropriate that process loads should be included in the Title 24 model for LEED NC v2.2 EAc1 compliance. Also, Title 24 is based on energy cost comparisons and these must be included with EAc1 documentation." "None" "None" "LEED Interpretation" "1582" "2006-10-09" "New Construction" "EAc1: Optimize Energy Performance" "We are working on a series of three projects on a campus. The three projects consist of a dormitory, an office building and a central chilled water plant that provides chilled water to various campus buildings, including the new dormitory and office buildings. Each of these three buildings is pursuing LEED separately. We assume that an average cost to produce chilled water will be calculated for the central plant on a dollars per ton-hour basis. In order to perform the EA credit 1 ECB calculations for the dormitory and office building that are pursuing LEED this cost per ton-hour will be applied to the total ton-hours of cooling needed according to the energy model (same cost for both the proposed and baseline building). The question relates to the central plant building. Since under LEED-NCv2.2 the EA credit 1 analysis requires examination of the total building energy use (both regulated and process loads) should the electricity used to create chilled water for the buildings other than the central plant be accounted for in the EA credit 1 calculation for the central plant building?" "No. Although the language in ASHRAE/IESNA 90.1-2004 may suggest including the entire chiller capacity as a process load when modeling the plant building, such an interpretation is ambiguous and in any case that method is inappropriate for LEED purposes. When calculating process energy use for a central chiller plant building\'s energy model, include only the percentage of the chiller plant capacity that is consumed within the central plant building itself. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1607" "2006-10-23" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "We are pursuing EA Credit 1, Option 2. We are using ""Advanced Energy Design Guide for Small Office Buildings"" (Achieving 30% Energy Savings over ASHRAE 90.1) in lieu of energy modeling, as allowed by LEED Reference. We are remodeling a historic building. Many ""Envelope"" items are existing conditions for this building. Would it be acceptable if we pursue an ""overall"" envelope that meets or exceeds the recommendations for envelope construction? For example, we will be able to exceed recommended R values in the roof, but we have some existing exposed brick that must remain un-furred. Or, can we exclude some existing conditions and historical conditions from our requirements for envelope R values and SHGC (for glass) values?" "The existing building project is seeking EAc1 credit using Option 2: the ""Design Guide for Small Offices"" compliance approach. The project is seeking an alternate envelope compliance approach using either an ""overall envelope"" approach or exclusions for existing and historical conditions. Exceptions and/or alternate compliance approaches are not permitted under EAc1 Option 2. The Design Guide for Small Offices was compiled based on multiple energy performance simulations that confirmed the cost-benefit of the recommended measures. The comparative benefits achieved through alternative compliance methodologies cannot be verified without additional energy simulation. Unless the project team can document that the project fully complies with all the prescriptive measures of the Design Guide for Small Office Buildings, a separate compliance path (either Option 1, or Option 3) must be taken to document points under EAc1. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1608" "2006-11-03" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "A private high school near Denver is a new campus that will consist of 3 main buildings - Arts, Athletics and Academics. The project is currently registered under LEED-NC 2.2 and we plan to use the LEED-NC Application Guide for Multiple Buildings and On-Campus Building Projects to guide us during design and documentation. The owner has chosen to register and pursue certification for the Academics and the Athletics buildings that are in the first phase of construction. They will be tracked and submitted together. The heating and cooling system consists of a central plant located in the Athletics building sized to provided chilled and hot water to all three main buildings (the two currently under design and the third that will follow at some point in the future). Should the energy model use the size of the chiller and boiler even though it is sized for all three buildings? Or should the energy model include a model for the proposed Arts building in order to more accurately determine part load performance and then subtract out the load of the other two buildings (all on a separate meters) when submitting the energy usage per building?" "The LEED project consists of two new buildings served by a newly constructed campus central plant. The central plant capacity is sized to include a building that will be completed in a future phase of construction. The project team is seeking clarification regarding how to model the capacities for the central plant equipment. For the Proposed Building case, the plant capacities (including chiller, boiler and cooling tower capacities, and circulation loop flow) should be scaled to represent the portion of peak thermal loads contributed by the buildings included in the LEED submittal. For example, if the projected peak chilled water loads are 200 tons for the buildings included in this LEED submittal, and 100 tons for buildings planned for future construction, the chiller capacity modeled for this submittal would be two thirds multiplied by the installed chiller capacity. Pump head should be modeled as reflected in the design documents. If the Baseline Building HVAC system type for the project includes a central plant, the type and number of chillers or boilers modeled for the Baseline Building shall be based on the conditioned floor area for the current LEED submittal. Similarly the Baseline chilled water and hot water pump controls shall be modeled based on the conditioned floor area for the current LEED submittal.\n\nUpdate April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues. " "None" "None" "LEED Interpretation" "1648" "2007-01-02" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "Our project is a new university campus building that is served by a central campus heating plant. The plant is comprised of biomass fueled boilers providing steam. However, the campus is considering a switch to fossil fuel as an alternative to biomass. Our question is two-fold: 1) We would like to confirm that it is appropriate to use the USGBC Combined Heat & Power (CHP) Reference Guide as a guidance document for the central heating plant, despite the fact that we are not generating electricity at the plant. 2) We would like to confirm that biomass feedstock used in a campus district heating facility would be considered free energy under EAc1." "An existing campus central plant fueled by biomass is used to supply heat to a new construction project. The project team is asking whether the USGBC CHP White Paper applies to central plants that are not generating power at the plant; and whether biomass feedstock used in a central plant facility would be considered free energy under EAc1. The USGBC CHP White Paper applies only to LEED v. 2.2 projects using combined heat and power. The USGBC is in the process of preparing a document describing the v2.2 modeling protocol for individual buildings serviced by a central plant without Combined Heat & Power. If the project would like to reflect performance improvements achieved from the central plant, they may apply the modeling methodologies described in this document (which will be available some time after January 2007). In the district energy document biomass is considered a non-traditional energy source and it is planned to base its cost on its carbon content versus the traditional fuel (it will likely not be free). If the project is completing documentation prior to the release of this document, then the both the Proposed and Baseline buildings should be modeled using the same purchased energy rates. If purchased energy rates are used, documentation should be provided justifying how these rates were determined. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1682" "2007-02-26" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "Our project is a 4 story 120,000 sq. ft. laboratory/classroom building with fossil fuel heat. Table G3.1.1A indicates that the baseline system should be packaged VAV with reheat (System 5). ASHRAE 90.1-2004 G3.1.1(c) indicates that if System 5 is our baseline, we should use separate single zone systems conforming to System 3 for any zones with special pressurization relationships or cross contamination requirements. Since the labs in our building have special pressurization relationships and cross contamination requirements, we are modeling the lab spaces with System 3 as the baseline per G3.1.1(c). The non lab spaces (without pressure or contamination requirements) will utilize System 5 as the baseline. It is not stated in ASHRAE 90.1-2004 G3.1.1 whether System 3 should be modeled with or without reheat. When we model the lab spaces with System 3 without reheat, we cannot maintain temperature and humidity at conditions acceptable for the experiments and for the occupants and the unmet load hours will not comply with G3.1.2.2. Modeling the lab spaces with reheat maintains the temperature and humidity compliance ranges of G3.1.2.2. These results were expected since these systems are near 100% outside air, and System 3 without reheat would not work for most labs in real life. In addition, ASHRAE 90.1-2004 6.5.2.1 (b) allows reheat for zones with special pressurization relationships and cross contamination requirements if VAV systems are impractical. While VAV systems are practical for this lab and are being used in the actual design, the minimum turn-down ratio required by G3.1.3.13 of 0.4 cfm/ft2 does not fall within the accepted current guidelines for Air Change Per Hour rates of OSHA (4-12), NFPA (min of 4), ASHRAE Applications (min of 3 for BSL-1 and min of 4 for BSL-2 spaces), and others in the same range of air flow rates. A typical lab space with a 9.5 feet ceiling height results in 0.63 cfm/ft2 at 4 ACHR, which is much higher than the required limit. ASHRAE 90.1-2004 G3.1.1(c) is specifically requiring us to use a constant volume system in the baseline but does not indicate any reheat limitations. Can System 3 have reheat for a lab baseline system? If not, please indicate the proper baseline system that would actually work for a laboratory space in real life, since System 3 without reheat or System 5 with a turndown ratio of 0.4 cfm/ft2 do not seem like acceptable baselines." "The project is requesting clarification for the system type selection for the specific project. If the proposed system is a VAV system and a VAV system is practical, the baseline system should be modeled as system 5 with the 0.4 cfm/ft2 requirement. It is important to note that the ASHRAE 90.1-2004 Standard Appendix G modeling protocol is not a compliance method but rather a method of comparing the proposed design\'s energy performance to a building that would have been typically built. Alternatively, the project may opt to model the VAV system as energy neutral and use the design minimum turn down ratios of the proposed design." "None" "None" "LEED Interpretation" "1693" "2007-02-26" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "We request the USGBC confirm our understanding that the 90.1-1999 ECBM and LEED modeling protocol allows us to receive credit for EAc1 energy cost savings for desuperheaters recovering heat from water source heat pump compressors, and using this heat to preheat service water heating, and that this can be done without an Exceptional Calculation, with the supporting discussion below. We understand that the heat recovery method would qualify as site-recovered energy as discussed under section 11.2.3 and its Exception, and is not included in the design energy cost, and the equivalent usage is met in the budget model by the backup energy source, which is electricity. Therefore, the measure is eligible for savings credit and to be modeled differently in the design model from the budget model. The desuperheaters and their heat recovery to service water heating can be readily modeled within eQuest and its computational engine, DOE-2.2, and therefore do not become an exceptional calculation for that reason. Therefore, the measure appears eligible for savings credit, and does not seem to require an exceptional calculation. Is this approach considered acceptable?" "The applicant is requesting clarification regarding whether desuperheaters must be modeled using the exceptional calculation methodology when the energy software program used for EAc1 compliance is capable of modeling heat recovery. The exceptional calculation methodology is only required when one of the following conditions are met: 1. The simulation program being used for the LEED EAc1 calculations cannot adequately model a design material or device 2. Input parameters that ASHRAE 90.1 requires to be modeled identically in the budget and proposed case must be modified to show the impact of the efficiency measure (e.g. schedule changes must be used to demonstrate improved efficiency, such as for demand control ventilation). 3. Previous LEED CIRs have mandated the use of the exceptional calculation methodology (e.g. - eQUEST is capable of modeling demand controlled ventilation, but since eQUEST accomplishes this by internally editing schedule values, the exceptional calculation methodology is still required for LEED v2.1 projects). In the case of desuperheaters, ASHRAE 90.1-1999 specifically requires condenser heat recovery to preheat service hot water under certain conditions (Section 6.3.6.2). Since heat recovery is prescriptively required under certain conditions, and since the software is capable of modeling desuperheaters without the use of supplemental spreadsheet calculations, the measure may be modeled without using the exceptional calculation method. The applicant should be sure to include all input assumptions regarding the desuperheaters in the input comparison table, and should provide sufficient information to confirm that condenser heat recovery does not have to be modeled in the budget case under the requirements of section 6.3.6.2. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1719" "2007-03-23" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "The project is a new City and County Courthouse in Denver. Many architectural spaces have high ceilings to bring additional daylight into spaces. To provide the required levels of lighting by IESNA with spaces with high ceilings, additional lighting must be provided. Title 24-2005, the California enegy code, can be utilized for energy compliance for projects in California. Title 24 has a lighting power density allowance for ceiling height. Additonally, a previous credit interpretation ruling found that the ASHRAE 90.1-1989 version of the energy code also had this lighting power allowance for ceiling height. Since Title 24-2005 can be used for energy compliance for projects in California, can the ceiling height lighting power density allowance also be applied to projects that are not in California? Height in feet above finished floor Multiply LPD by 12 or less 1.0 13 1.05 14 1.10 15 1.15 16 1.21 17 1.47 18 1.65 19 1.84 20 or more 2.04 Source: California Title 24-2005" "The applicant is requesting clarification whether certain components of the Title-24 2005 energy code can be applied to projects that are not in California. Title-24 2005 energy code may only be used for compliance by projects that are in California. Furthermore, the prescriptive requirements for Title-24 standards may not be applied to ASHRAE 90.1 models, and prescriptive requirements for ASHRAE 90.1 standards may not be applied to Title-24 models. The project may not use the Title-24 lighting multipliers described above for projects that are not in California." "None" "None" "LEED Interpretation" "1734" "2007-03-22" "New Construction, Commercial Interiors, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "Our project consists of two small buildings close to the ocean that will achieve substantial energy savings by incorporating a natural ventilation strategy. No mechanical heating or cooling is intended for either building, with the exception of a small electrical/server room. The building is designed with a very narrow and long floor plate situated perpendicular to prevailing winds in the area. Ventilation openings are consistent with the requirements of ASHRAE 62.1-2004 Section 6.8. The project also meets the requirements outlined in the CIBSE Applications Manual 10: 2005 as referenced in EQc2 for Natural ventilation in non-domestic buildings. Per Title-24 2005 requirements for natural ventilation, the sum of operable windows will be greater than 5% of the floor area of each space that is naturally ventilated. The openings will also be readily accessible to the occupants of each space at all times. Outdoor airflow through the openings in regularly occupied spaces will come directly from the outdoors, not through intermediate spaces such as other occupied spaces or corridors. Openings include operable windows, through-the roof ventilators, and vents between interior spaces. Control mechanisms for the natural ventilation openings are manual. A long, tall hallway situated perpendicular to the prevailing winds will collect heated air and exhaust it the outside. The roof over much of the space is sloped allowing air to enter on the low side and exit on the high side. In all cases, the building is designed to facilitate cross-ventilation with windows low on the walls for drawing the air in, and windows and vents high in opposite walls or on the roof to draw air out. Under ASHRAE 55 definitions, the building spaces are defined as ""naturally conditioned spaces, occupant controlled"" where the thermal conditions of the spaces are regulated primarily by the opening and closing of windows or vents by the occupants. Since the building will have a limited number of occupants most of the time, manual control of the windows and vents has been determined the most appropriate strategy for the building to allow control over individual thermal comfort. As indicated by ASHRAE 55-2004, section 5.3, the occupants of the space will be engaged in near sedentary activities with metabolic rates ranging from 1.0 met to 1.3 met. The mean monthly outdoor temperature for the project is greater than 50 deg. F, and less than 92.3 deg. F all months of the year, as required under ASHRAE 55-2004, section 5.3 for naturally ventilated buildings. The User\'s Manual for ASHRAE 90.1-2004 Appendix G states on page G-21: The proposed building default cooling system does not exclude natural ventilation from consideration. It just means that the proposed building is modeled as a hybrid system where cooling is provided by natural ventilation when conditions are acceptable and by the default mechanical cooling system when natural ventilation is inadequate to provide thermal comfort. We are requesting confirmation that the following modeling strategy conforms to the requirements of ASHRAE 90.1-2004 Appendix G modeling protocol: 1. EnergyPlus will be used to model the building since the EnergyPlus software has the capability to evaluate energy and comfort parameters tied to natural ventilation. 2. The Exceptional Calculation Methodology will be applied to calculate the natural ventilation savings. 3. The Proposed Design model will be developed to reflect the design parameters for the envelope and lighting. Operable windows will be modeled as fixed, and vents will not be included in the model. Mechanical systems will be modeled identically to the default heating, cooling and fan systems in the Baseline case, except that fans in the proposed case will be modeled as cycling on and off to meet heating and cooling loads during all hours in the proposed case, and will operate continuously during occupied hours in the Baseline Case (per the exception shown in Table G3.1.4). 4. Using the Exceptional Calculation Methodology, The Proposed Design case will be modified to include natural ventilation for all hours when the cooling and heating loads can be met. Operable windows and vents will be modeled as designed. Cooling and heating setpoint temperatures will be identical to those in the Baseline Case. Schedules will be adjusted to switch on mechanical cooling during hours when natural ventilation alone cannot meet the space temperature setpoints. The final model will meet the ASHRAE G3.1.2.2 requirements stipulating that the Proposed Design cannot exceed the Baseline Design unmet load hours by more than 50, and that unmet load hours for the Proposed Design and Baseline Design cannot exceed 300. 5. (Plan B) If the hybrid system cannot be manipulated to meet the unmet load hour requirements within the energy model, hourly output data from a natural ventilation model (having no mechanical cooling) and the Proposed Design model will be combined in a spreadsheet. Each hour where cooling and heating setpoints are met in the natural ventilation model, the hourly results for that model will be used. For all other hours, the hourly results from the Proposed Design Model will be used. 6. An Exceptional Calculation Methodology narrative provided with the EAc1 submittal will document any schedule adjustments and assumptions that were made to develop the hybrid system. The savings will also be included as a separate line item on the EAc1 submittal. Is our proposed energy modeling strategy for natural ventilation acceptable?" "The project is requesting approval for the method of modeling natural ventilation as an energy efficiency measure and for taking credit under EA credit 1. Submittals for natural ventilation savings will be evaluated on a case by case basis. The tools and analysis protocol proposed is acceptable for modeling ventilation savings in this instance. Other analysis tools may also be appropriate. To be able to adequately document the process and the results, please be sure to provide in the LEED submittal the following: " "2095, 5152" "None" "X" "LEED Interpretation" "1756" "2007-05-13" "New Construction" "EAc1: Optimize Energy Performance" "Our project involves a new 817,000 square feet facility for the production and storage of multiple milk-based products. The project is targeting a LEED Silver certification, which includes earning points under EAc1 for modifying the manufacturing process, improving equipment efficiency and controls. As process loads exceed ""regulated"" loads, it is anticipated that process energy efficiency improvements will comprise the majority of energy savings for the project. Due to the nature of the project, the following issues must be resolved in order to complete the EAp2 and EAc1 analysis: The identification of the building portions that are regulated under ASHRAE Standard 90.1-2004 The method for demonstrating that the regulated spaces meet EAp2 requirements The method for calculating energy savings under EAc1 for both the regulated and unregulated building portions Through this CIR, the team requests the acceptance of the following methods for addressing the issues outlined above. ASHRAE 90.1 Regulated Spaces The facility can be categorized into four conditioned space types and the utility plant as outlined in Table 1. Space Floor Areas and Indoor Conditions: Spaces are : Office 50,000 s.f. Ref. Warehouse 225,000 s.f. Processing 118,000 s.f. Packaging 331,000 s.f Utility Plant 92,000 s.f. Summer indoor design conditions are: Office (75F-50%), Ref. Warehouse (42F-50%), Processing (68F-50%), Packaging (80F-60%) and Utility Plant (NA) Winter Design Conditions are: Office (72F), Ref. Warehouse (42F), Processing (60F), Packaging (60F) and Utility Plant (NA) Section 2.3 of ASHRAE 90.1-2004 states that the standard does not apply to ""equipment and portions of buildings that use energy primarily to provide for industrial, manufacturing or commercial processes."" Process energy is further defined as ""energy consumed in support of a manufacturing, industrial, or commercial process other than conditioning spaces and maintaining comfort and amenities for the occupants of a building."" The team interprets this statement to mean that the standard does not apply to building portions that have indoor conditions dictated by process requirements instead of occupant comfort conditions. E.g, this obviously exempts refrigerated warehouse areas. Based on this interpretation, the team believes that the office and the packaging spaces are regulated by ASHRAE but the other spaces are not (footnote 1). EAp2 Approach To meet EAp2 requirements, the team proposes to demonstrate that the ASHRAE regulated spaces meet the energy performance requirements through a prescriptive or performance-based approach(footnote-2). Since the majority of savings anticipated under EAc1 will come from process loads occurring in the unregulated spaces, the option to show EAp2 compliance by using the results of the Performance Rating Method would not be appropriate. EAc1 Approach The following methodology is proposed for the EAc1 analysis: The EAc1 savings for the regulated building portions will be determined using the PRM without modification. The baseline model for the unregulated building portions will generally be the same as the proposed model and will be based on the schematic design documents. Process energy use in the baseline and proposed models will be calculated as noted below, and added to the respective results. As already alluded to, the process equipment uses most of the energy in this facility (e.g. the new substation service is sized at 30 W/sf). Most savings anticipated for the project will result from reducing process loads and process energy use. Since these components are not regulated under ASHRAE, an exceptional calculation method (ECM) will be followed to quantify savings. As part of this, the EAc1 submittal will include documentation of the assumed baseline system configurations and performance calculations and the same information for the proposed building. Characteristics that change between the baseline and proposed buildings will be clearly outlined as part of each ECM presentation. We anticipate that spreadsheet methods will be used to calculate most of process energy savings. Footnotes: (1) the process space has low humidity requirements that can not easily be met by the 44F chilled water temperature dictated for a baseline CHW system in the Performance Rating Method. (2) If a performance-based approach is used, the unregulated building portions will be considered to be energy neutral" "The applicant has posed a multi-level request to determine eligibility and as a next step to demonstrate optimized energy performance for their project which is a new 817,000 square feet facility for the production and storage of multiple milk-based products. The applicant\'s classification and approach for the spaces appears reasonable with the following exceptions - 1. For the process load areas, 100% of that area will not be dedicated to the process itself. If there are support areas (offices, control rooms, restrooms, etc.) in those buildings, they should be considered regulated and removed from the process load classification. 2. The Refrigerated Warehouse envelope must comply with ASHRAE 90.1-2004 section 5. All other elements of this facility must be able to demonstrate compliance with ASHRAE 90.1-2004 sections 5 through 10 either prescriptively, or using section 11 Energy Cost Budget Method to comply with EAp2. 3. It is not clear from the narrative how many models will be created for the project. If this is a single facility, it would be required to be dealt with as a single model for the purposes of EAc1. Please refer section 3 Table G.3.1. If the project is anticipating any synergies between the Utility Plant and the rest of the project in terms of energy recovery etc., then all components of the utility plant needs to be part of the simulation. If the simulation software cannot handle any component, it must be considered energy neutral and any savings taken as exceptional calculation. 4. The narrative states that most of the savings will be from process energy reduction; however no baseline has been defined for the process energy. Since this type of energy consumption is not under the purview of ASHRAE 90.1-2004, the baseline used to compare energy performance becomes critical. It might be useful for the project team to submit a separate CIR outlining the proposed process energy baseline." "10291" "None" "LEED Interpretation" "1763" "2007-05-14" "New Construction" "EAc1: Optimize Energy Performance" "Per ASHRAE 90.1-1999 and 2004 mandatory requirements, hotel guestrooms must include a master control device at the main room entry that controls all permanently installed luminaires and switched receptacles. We are considering automating this lighting control with the use of a key card-activated master switch. The control would turn off all permanently installed and switched receptacle lighting after the guestroom is unoccupied for more than 30 minutes. The controls may also be configured to allow the interior window shades to be closed automatically when the guestroom is unoccupied. Monitored data for hotel lighting usage patterns is provided in a 1999 Research study by Erik Page and Michael Siminovitch entitled ""Lighting Energy Savings in Hotel Guestrooms."" This study indicates an average daily usage of nearly 8 hours for the bathroom light, 2 hours for the desk table lamp, 5 hours for the bedside lamp, and 3 hours for a floor lamp. The study also showed that the high use fixtures (the bathroom fixture and bed lamp) did not experience a significant drop during typically unoccupied periods. Instead, these lights were 20% - 25% on during these periods; and the lighting energy consumed during these periods accounted for about 60% of the total guestroom lighting energy consumption. Another study for ACEEE entitled the ""Emerging Energy-Savings Technologies and Practices for the Building Sector as of 2004"" projects an energy savings for key card lighting controls of 30%. Based on the information provided in these two studies, it seems reasonable to credit hotel guestroom lighting fixtures with a 30% energy savings for automated control based on room occupancy. We propose to model the energy savings achieved through automated control of lighting and interior window shades as an exceptional calculation measure. The lighting savings would be calculated by adjusting the proposed case lighting schedules for all permanently installed and switched receptacle fixtures to 50% lower than the budget case for the percentage of guestrooms modeled as unoccupied. Lighting during all occupied periods will be modeled identically to the budget case. The guestroom lighting energy savings achieved through this measure for the affected lighting fixtures would be 30%. Automated control of the blinds is intended to limit solar heat gains, since the building is in a hot dry climate. The blinds will be modeled identically during the occupied periods as 50% open during daylit hours, and 25% open during evening hours. During unoccupied periods, the shades will be modeled as 25% open. As with all exceptional calculation measures, the savings for this automated control measure will include a narrative documenting the lighting and interior shading schedules and assumptions, and the calculation methodology, and will include a separate line item on the ECB report documenting the savings achieved from this measure. We would like confirmation whether the proposed modeling methodology is acceptable, or direction regarding any modifications that would need to be made to the proposed modeling methodology in order to comply with LEED ECB modeling requirements." "The applicant is requesting confirmation on the proposed strategy for two exceptional calculations. Based on the description of the lighting assumptions, the proposed approach is acceptable. In the LEED submittal please include a narrative documenting the lighting schedules and assumptions and the calculation methodology. Also include a separate line item on the ECB report documenting the savings achieved from this measure. Please provide enough detail in the documentation to allow the review team to ascertain the amount of credit claimed. Based on the description of the automated blinds, the assumptions concerning blind control are insufficient to model the proposed building." "None" "None" "LEED Interpretation" "1818" "2007-08-13" "New Construction" "EAc1: Optimize Energy Performance" "This CIR is a follow-up to the 2/26/2007 ruling for our 120,000 sq. ft. laboratory project. The EAc1 ruling dated 2/26/2007 indicates ""the project may opt to model the VAV system as energy neutral"". Does this include the exhaust fan system? G3.1.2.9 indicates the baseline ""System fan electrical power for supply, return, exhaust and relief (excluding power to fan powered VAV boxes) shall be calculated using the following formulas"". This formula listed may be suitable for determining baseline fan power in an office, but it seems like the fan power for any lab building would significantly exceed this number because of the exhaust fan requirements, pressure drop through fume hoods and exhaust air valves, etc. For example, a typical lab could have 0.01 to 0.05 inches of room differential pressure, plus 0.5 inches drop through the fume hood, plus 0.2 to 0.6 inches through the exhaust air valve, and plus 0.75 to 1.5 inches through the exhaust HEPA filter. This totals to about 1.46 to 2.65 inches of additional pressure drop for a lab exhaust system vs. office exhaust. The lab exhaust may also have about 0.5 inches of additional pressure drop associated with generating stack velocity on the discharge of the fan. Lab exhaust will have a slight pressure drop reduction from office exhaust since the lab system will not have fire dampers (0.2 to 0.3 inches), but this is not enough to offset all the other lab system pressure drops. For our specific project, we have modeled both the baseline and proposed case as VAV systems per the 2/26/2007 ruling. When we use G3.1.2.9 to calculate the supply and exhaust fan power in the base case and we model the proposed case with our actual supply and exhaust fans, the proposed case fan power is more then double the base case due to the exhaust fans. The proposed case fan power is greater then 500,000 kwh per year while the base case is closer to 200,000 kwh per year. For our proposed model, both the supply and exhaust are variable speed with high efficiency motors, but we are still penalized on fan power when comparing to the base case using G3.1.2.9. Can the VAV exhaust in a lab be modeled as energy neutral?" "The applicant is requesting further clarification on CIR ruling dated 2/26/2007. The applicant may utilize Addendum ac of ASHRAE Standard 90.1-2004 as well as the related changes to Appendix G to get credit for the pressure drop associated with laboratory exhaust systems. Addendum ac modified the fan power allowance in Section 6 of Standard 90.1. Included in this modification is an exemption for the fans exhausting air from fume hoods. When these fans are exempted, the allowed horsepower for the entire system is required to be reduced by an adjustment factor contained in TABLE 6.5.3.1.1B. When Addendum ac was developed, the related section of appendix G was also modified and those changes are reproduced below. These changes to Appendix G as well the requirements of Addendum ac may be used by the applicant. ************************ G3.1.2.9 Supply Fan Power. System fan electrical power for supply, return, exhaust, and relief (excluding power to fan-powered VAV boxes) shall be calculated using the following formulas: For Systems 1 and 2 Pfan = CFMS * 0.3 For Systems 3 through 8 Pfan = bhp x 746 / Fan Motor Efficiency where Pfan = electric power to fan motor (watts) and bhp = brake horsepower of baseline fan motor from Table G3.1.2.9 Fan Motor Efficiency = the efficiency from Table 10.8 for the next motor size greater than the brake horsepower using the Enclosed Motor at 1800 RPM CFMS = the baseline system maximum design supply fan air flow rate in cubic feet per minute TABLE G3.1.2.9 Baseline Fan Brake Horsepower: Baseline Fan Motor Brake Horsepower: Constant Volume Systems 3 - 4 // Variable Volume Systems 5 - 8 CFMS * 0.00094 + A // CFMS * 0.0013 + A Where A is calculated according to 6.5.3.1.1 using the pressure drop adjustment from the proposed building design and the design flow rate of the baseline building system. Do not include pressure drop adjustments for evaporative coolers or heat recovery devices that are not required in the baseline building system by Section G3.1.2.10. ************************" "None" "None" "LEED Interpretation" "1819" "2007-08-13" "New Construction" "EAc1: Optimize Energy Performance" "This CIR is a follow-up to the 2/26/2007 ruling for our 120,000 sq. ft. laboratory project. The EAc1 ruling dated 2/26/2007 indicates ""the ASHRAE 90.1-2004 Standard Appendix G modeling protocol is not a compliance method but rather a method of comparing the proposed design\'s energy performance to a building that would have been typically built."" The prescriptive requirements in 6.5.7.2 of ASHRAE 90.1-2004 indicate fume hood systems having a total exhaust rate greater than 15,000 cfm shall include either VAV exhaust and room supply, direct make-up, or heat recovery systems. Based on these prescriptive requirements, a lab similar to ours would that would have been typically built would not include both VAV and energy recovery. It would only include one of these strategies. But based on the 2/26/2007 ruling, it seems the baseline in Appendix G will require both VAV and energy recovery, which is above the typical based on the prescriptive requirements noted above. The 2/26/2007 EAc1 ruling indicates ""the baseline should be modeled as system 5"", meaning we should ignore G3.1.1(c) (which tells us to model our baseline in the lab only as constant volume) and we should model the baseline lab as a VAV system. G3.1.2.10 requires us to have energy recovery in the baseline since we also have it in the proposed design. By having us ignore G3.1.1(c), the 2/26/2007 ruling has created a baseline that is above the typical. This ruling does not award labs for providing both VAV and energy recovery even though having both is not typical. Can we instead match the prescriptive requirements and typical lab building design by not including energy recovery in the baseline with VAV when we do have energy recovery in the proposed design?" """The applicant is requesting an allowance to match the prescriptive requirements of Standard 90.1 in their baseline building model. This request is allowed. Section 6.6.7.2 of Standard 90.1-2004 requires the proposed laboratory system to include either VAV controls that are capable of reducing exhaust and makeup air volume by 50% of design values or heat recovery meeting the requirements of Section 6.5.6.1. This is consistent with the applicants request to not include heat recovery in the baseline building model. In addition, the baseline VAV system serving the laboratory should only reduce the exhaust and makeup air volume to 50% of design values during unoccupied periods instead of the minimum volume setpoint of 0.4 cfm/ft2 of floor area as required by Section G3.1.3.13.""" "None" "None" "LEED Interpretation" "1820" "2007-08-16" "New Construction" "EAc1: Optimize Energy Performance" "This credit interpretation request is in reference to the modeled baseline HVAC system. The project is a 142,000 sqft health care facility to be built in Northern Italy. Two questions arise due to the location and use of the building. 1) The pressurization and air change requirements of a health care facility meet exception (c) of G3.1.1 which indicates System 3 - PSZ-AC is to be used as the baseline system. A single zone constant volume system is unable to adequately meet the temperature and humidity control requirements without reheat and would not be used in this type of facility. Omitting the reheat capabilities of the baseline system puts the design model at an extreme disadvantage when comparing energy use and does not seem to meet the intent of the standard. It is proposed that for this project reheat also be included in the baseline model to account for the temperature and humidity control requirements of a health care facility. 2) Italian health care facilities require substantial fan energy due to high air change rates, AHU components and duct accessories compared to other facilities such as office buildings. The intent of this section 3.1.2.9 was to enable credit for and encourage more efficient fan systems. The only pressure credit given is for systems requiring filtering systems in excess of 1 in. w.c. static pressure. Air pressure drops associated with cooling coils, preheat coils, multiple filter stages, air blenders, extensive sound attenuation required by Italian law, humidifiers, exhaust bio-safety cabinets, and excessive number of fire and smoke dampers due to Italian law all contribute to the excessive fan energy required. It is proposed this calculation not be used to penalize the design model for meeting Italian health care facility requirements and to determine the baseline system fan power on the same static pressure as the proposed design. Great effort was put forth to provide an energy efficient HVAC design while meeting or exceeding the design requirements. Both of the issues stated penalize this effort and therefore would not be the intent of the standard." "The project team is requesting direction regarding energy modeling of HVAC systems for a health care facility. Two issues are raised; humidity control and fan power characteristics. These parameters can vary substantially from a typical office building and as indicated by this CIR, the 2004 version of Appendix G has some limitations when addressing health care facilities. Regarding the first issue, this CIR states that a single zone, constant volume system is unable to meet temperature and control requirements without reheat. This is true, and is an issue for any application that has humidity control requirements (such as a telecom or server room). ASHRAE 90.1-2004 Table G3.1 Proposed (b) states that temperature and humidity control setpoints shall be the same for the proposed and baseline building designs. The design team should follow the Appendix G requirements and model those spaces with pressurization control requirements with System 3 -PSZ-AC in the baseline building. Humidity control requirements should be the same as in the proposed building, even if that requires reheat to be modeled with that system type. The second issue; fan power is not adequately addressed by the 2004 version of Standard 90.1 for healthcare and laboratory applications. Addendum ac to Standard 90.1, and related changes to Appendix G have been adopted by ASHRAE, and will be published in the 2007 version of the Standard. These changes specifically address the issues raised by the project team, and may be used for this project. Included in Addendum ac are added pressure drop credits for fan systems that include evaporative cooling, sound attenuation, ducted returns, filtration, and return or exhaust airflow control devices. These credits are contained in TABLE 6.5.3.1.1B of addendum ac. The corresponding changes to Appendix G were not published with Addedum ac, but are reproduced below. The changes to Appendix G as well the requirements of Addendum ac may be used by the applicant. ********************************************************************************************************* G3.1.2.9 Supply Fan Power. System fan electrical power for supply, return, exhaust, and relief (excluding power to fan-powered VAV boxes) shall be calculated using the following formulas: For Systems 1 and 2 Pfan = CFMS * 0.3 For Systems 3 through 8 Pfan = bhp x 746 / Fan Motor Efficiency where Pfan = electric power to fan motor (watts) and bhp = brake horsepower of baseline fan motor from Table G3.1.2.9 Fan Motor Efficiency = the efficiency from Table 10.8 for the next motor size greater than the brake horsepower using the Enclosed Motor at 1800 RPM CFMS = the baseline system maximum design supply fan air flow rate in cubic feet per minute TABLE G3.1.2.9 Baseline Fan Brake Horsepower Baseline Fan Motor Brake Horsepower Constant Volume Systems 3 - 4 // Variable Volume Systems 5 - 8 CFMS * 0.00094 + A // CFMS * 0.0013 + A Where A is calculated according to 6.5.3.1.1 using the pressure drop adjustment from the proposed building design and the design flow rate of the baseline building system. Do not include pressure drop adjustments for evaporative coolers or heat recovery devices that are not required in the baseline building system by Section G3.1.2.10." "None" "None" "LEED Interpretation" "1832" "2007-08-13" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a large dedicated Data Center facility with 100,000 sq. ft. of raised floor, 100,000 sq. ft. of mechanical infrastructure equipment space, 80,000 sq.ft. of electrical infrastructure equipment space, and 10,000 sq. ft. of normally occupied office space. The annual electrical power consumption for the computing equipment of this dedicated data center is 82,820,000 KWH, which represents 78% of the annual total building energy cost at 105,630,000 KWH. In general the LEED rating system was not developed with a unique facility type, such as data centers, in mind. Some of the LEED credits do not apply, such as EQ C6.1, 6.2, 7.1, 7.2, 8.1 and 8.2, while other LEED credits are cost prohibitive to achieve, such as EA C3, EA C5 and EA C6. Under LEED NC2.1, after the entire electrical utility costs were calculated for the baseline and proposed energy modeling, the electrical utility costs of the process load were subtracted out for both models. The resulting energy savings percentage was used to calculate the LEED points. Under LEED NC2.2, the electrical utility costs for the process load cannot be subtracted out. For Data Center facilities, the process load is a very large percentage of the total energy consumption. The total energy savings from the HVAC and electrical systems with respect to the baseline model is far less than the identical building without a large data center. As a result, NC2.2 calculation method ""dilutes"" the savings gain from the building infrastructure systems and is not a fair comparison with respect to other typical commercial buildings. It also makes it more difficult for a high process load building to achieve credits in optimizing energy performance, on-site renewable energy and green power. Even ASHRAE 90.1-2004, section 2.3C, also indicates that the standard does not apply to the data processing area: ""portions of building systems that use energy primarily to provide for industrial, manufacturing or commercial process."" According to the CIR submitted 2/28/2007 and ruling on 3/23/2007, a 92,000 sqft office building with 5,000sqft data center project encountered a similar situation and requested a credit interpretation. The CIR cited the ASHRAE 90.1, appendix G and allowed the project to use system 3 or 4 (a packaged single zone system) as the modeling baseline. However, it is the industry standard of utilizing multiple single package, constant speed, cooling system (CRAC, Computer Room Air Conditioning Units) for data center cooling. The use of CRAC Units are widely accepted and published in various ASHRAE data center design guidelines, including ""Design Consideration of DataCom Equipment Centers, ASHRAE, 2005"" and ""Thermal Guidelines for Data Processing Environments, ASHRAE, 2004"" As a result, the CIR correctly set the modeling baseline to the industrial standard. But it does not necessary address the disadvantage that the high process load building experiences as compared to a typical commercial building. For our project, following the NC2.2 calculation in accordance with this CIR, we calculated only a 15.5% reduction using all commercially available strategies, including better walls, roof and windows, a higher efficient chiller, VFD AHUs, VFD pumps, VFD cooling towers, occupancy sensors and reduced lighting density. In order to fairly evaluate energy savings of the enhanced building envelope and infrastructure systems, the energy saving calculation should be focused on non-process building efficiency improvements. Therefore, we are requesting an interpretation of the credit that would allow us to exclude the energy consumed by the data center computing equipment from the energy simulation calculations. Our modeling would then use the baseline system as discussed in the 2/28/2007 CIR and our proposed system, a highly efficient, but much higher cost, central chilled water system." "The project is requesting exclusion of the energy consumed by the data center computing equipment from the energy simulation calculations. The 3/23/2007 CIR ruling adequately addresses the same request, and holds for this inquiry as well. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1844" "2007-08-13" "New Construction" "EAc1: Optimize Energy Performance" "INTRODUCTION: Our project is a 239,122 SF brick manufacturing facility in Terre Haute, Indiana. The project consists of 6,122 SF of air-conditioned office space, control rooms and electrical room, and 233,000 SF of non-conditioned manufacturing area, that includes extrusion, drying, and kiln equipment. The energy required for the manufacturing process exceeds 95% of the facility\'s total energy load. Since industrial energy usage does not fall under purview of ASHRAE 90.1-2004, and in accordance with Credit Interpretation Ruling by USGBC and EA TAG for NCv2.2 EAc2 dated 06/15/2007, an alternative compliance path must be established for the manufacturing portion of the facility. Additionally, our Client has selected a site that is directly adjacent to a municipal landfill, with plans to fuel the kiln with methane off-gassing from the landfill. Our Client has obtained permission from the landfill to tap into this energy source. As part of our project scope, we will install compressors and an underground pipeline to transport the landfill gas to the manufacturing facility. The 06/15/2007 CIR ruled that, among other things, this system does qualify as ""on-site renewable energy,"" provided that process energy is included in energy loads for EAc1 and EA prerequisite 2. APPROACH: For the fully conditioned portion of the facility we will use ASHRAE 90.1-2004 Appendix G performance Rating Method. Pursuant to the EAc2 CIR dated 06/15/2007, an alternative compliance path will be established for the manufacturing portion of the facility. Those two energy saving results will be combined to fill out the EAc1 Submittal Template and come up with overall cost savings for the whole facility. The methane from the landfill will replace the majority of natural gas that powers the kiln and vastly reduce the amount of on-grid energy required by the facility. During facility operation, a 25% of natural gas (supplied from the local natural gas utility company) and 75% of landfill gas will be utilized for facility needs (these numbers are conservative and are used for calculations). Please verify that the following methodology may be used to calculate baseline and design case process loads and the resulting energy savings. PROPOSED COMPLIANCE PATH FOR PROCESS LOADS: a) Manufacturing process baseline: the gas usage baseline model is established based on the historical operational data for fiscal year 2006 for all 21 US brick manufacturing operations. The equivalent established as the measure of kiln efficiency is ""BTU of energy required per pound of standard brick."" Plant operations monitor and record how many BTUs per pound of brick are required over time and those data establish a yearly average (BTU/pound) for the given facility. Calculated averages are then summed up for all 21 US locations to come up with an overall mean value representing the average kiln efficiency. Also, baseline usage is calculated using 100% natural gas supplied by the local natural gas utility company, which is the brick industry standard. The cost of gas is based on the NYMEX published value of $6.44/Mbtu, which is within a fraction of a percent of the local natural gas utility company (Ohio Valley Gas, Inc.) charge. Natural gas usage for infrared heating and potable water heating within manufacturing area is assumed to be the same for both the baseline and design case. Electrical baseline usage is established based on the historical data for the plant of the similar size and capacity (manufacturing facility in Phenix City, Alabama). Design connected electrical load for manufacturing equipment at this location is 2800kW. Diversity factor ranges from 55% to 75% - diversity factor represents ratio of peak demand kW and design connected load. Electrical energy usage in kWh represents actual plant electrical consumption. b) Manufacturing process proposed alternative: the proposed model is based on actual predicted plant operations with 75% landfill gas usage, and 25% natural gas usage coming from the local utility company. The contractual landfill gas charge is 50% of NYMEX published value. The kiln efficiency was set to be manufacturers guaranteed maximum value of 820 BTU/pound (in reality, and based on the previous experience, this number will vary and can be as low as 670 BTU/pound). Electrical proposed usage is established based on the design parameters for new plant and operational factors obtained from the historical usage data for the existing baseline model. Design connected electrical load for manufacturing equipment for proposed design is 2150kW. Diversity factor is set to be 75%. In order to minimize trade-offs between the diversity factor for the baseline and design case, the proposed design represents the maximum diversity factor figure obtained from baseline model (most conservative approach). Electrical energy usage in kWh is calculated by applying the hourly factor of consumption to peak plant demand. The hourly factor is empirically obtained from the baseline model. c) To determine percentage of renewable energy cost, proposed model will be compared to the model of same efficiency but with 100% natural gas supplied from the local utility company. Credit Interpretation Request: Please confirm that our conservative assumptions and method of calculating the process energy load for both the base and proposed design cases are acceptable for EAc1." "The CIR is requesting approval of the proposed Exceptional Calculation Methodology to document energy savings in a manufacturing process. The method appears acceptable, provided: [1] The utility rate used in the energy model should be the same for the baseline and design case. [2] When determining the manufacturing process energy baseline (for natural gas and electrical usage), the comparison should be made to a standard practice/new equipment facility. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1845" "2007-08-07" "New Construction, Commercial Interiors, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "Background: Our project is the 25,000 sf expansion of a school campus including three new buildings - two 1-story structures and one 2-story structure. Our goal is to lower energy use as much as possible, including the selection of process load appliances with low energy use. All of the new spaces in the three new buildings are complete build outs, except four classrooms in the 2-story structure that are being built out as core and shell spaces only. These classrooms will be a low-scale lab environment, metal shop, wood shop or some very light work shop component as yet not defined and will be finished as a future tenant improvement. The scope of our current project does not include the installation of any plug or process load equipment for the core and shell space, only HVAC (heating and basic ventilation only, none for process equipment) and lighting shall be installed. The overall core and shell area of this project is relatively small (3000sf) compared to the overall project area. Proposed Modeling Strategy: For the purposes of documenting the baseline and proposed energy use of this combined full build out and core and shell project, we propose the following methodology. For all completely built out spaces, create a model with baseline energy use including process loads at 25% of total baseline building energy use. The proposed case for the fully built out spaces would have the envelope, systems, lighting and process loads modeled as designed, with documentation available for the new process loads. For the core and shell spaces, since these do not have any associated plug or process loads to be installed at this time, we propose to create a separate model for these spaces that only addresses envelope, lighting, domestic hot water and HVAC systems. This model would provide baseline and proposed case annual energy use for these non-process load related components. Once the annual energy use figures are available for both the full build out and core and shell spaces, it is proposed that the baseline energy use figures be added together for both cases to achieve an overall baseline energy use for the project. Similarly, the proposed case annual energy use would be the combined proposed energy use of the fully built out and core and shell spaces. In this way, an accurate representation of the scope of the project can be modeled for both baseline and proposed cases. Request: Please confirm that the following approaches are acceptable to accurately demonstrate the condition of the proposed building. 1. Is it acceptable to keep the baseline process load energy cost at 25% of the baseline total energy cost, while modeling and inputting the actual installed process loads for the proposed case? This would allow the building to achieve some credit for specifying lower energy use plug and process load equipment than a baseline case. Note that the proposed process energy costs may or may not be 25% of the total energy cost, and may or may not be equal to the process energy load for the baseline case. 2. Is it acceptable for the core and shell spaces to not include process loads in the total energy cost for either the baseline or proposed cases? This would most accurately reflect the project condition. Process loads would be included in the model simulation for the purpose of demonstrating heating and cooling load compliance only, but would be separated out when determining total energy cost for the core and shell spaces. 3. Is it acceptable to create two separate building models for the project, one for the full build out portion of the project and a separate model for the core and shell portion? The core and shell model would exclude process energy cost from its total energy cost. Is it acceptable to sum the total energy costs of the full build out and core and shell spaces to achieve the total project energy cost?" "The questions will be addressed in the order that they were presented: [1] It is acceptable to vary the design case process load to reflect energy efficiency measures (ie Energy Start Appliances) that affect the process energy load. This is considered an Exception Calculation Method (ECM) and thus full documentation should be provided justifying the differences and highlighting the assumptions and inputs that were used to create both the baseline and design case process energy loads. It is not allowable to use the default 25% process load value for the baseline case if the proposed case process energy has been inputted piece-by-piece (for example, by inputting the energy usage for each computer, copier, etc.). Instead the baseline model must also have piece-by-piece inputs using identical input power and energy rating as the proposed case unless the applicant can demonstrate that the proposed equipment represents a significant verifiable departure from documented conventional practice. In that case, the values for conventional practice may be used for the baseline equipment with the same use schedule as the proposed case. [2] It is NOT acceptable to ignore process energy usage in future build-out spaces. The LEED Core & Shell Reference Guide provides some guidance in how to address future build-out spaces, though it is more geared to address tenant-leased spaces. Key concepts to follow for future build out spaces include, but are not limited to: [A] Model receptacle and other loads (process) based on estimates for the building type. Table G-B of the ASHRAE 90.1-2004 User\'s Manual (note, this is not the same document as the ASHRAE 90.1-2004 Standard) provides acceptable receptacle power densities, occupancy densities, and hot water usage for varying occupancy types. [B] Use the same values for receptacle and process loads in both the baseline and design cases for the future build-out spaces. [C] If default values cannot be found for certain occupancy types, make reasonable estimates based on modeling and design experience. Please note where these values were used and what estimates are based on. [3] Separate building models for the full build-out and core and shell portions of the project are not recommended. Energy usage calculations are compromised when the model is broken apart because, among other issues, the model is no longer able to apply diversity factors across all project spaces or properly size systems based on peak demand. It may be permissible to separate portions of the model for an ECM, but this is only in the case that limitations in the modeling software prevent adequate representation of the design. If this is the case, full ECM documentation will need to be provided, as described in ASHRAE 90.1-2004 G2.5. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1847" "2007-08-13" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "Background: Our project is a 28,000 sf, two-story MBA educational and office building on a college campus. Our goal is to achieve up to 10 points under the EA c1.2 category. To that end, we are committed to reducing process loads, along with the other measures in the integrated building design to reduce overall energy use. This project primarily has office equipment as the majority of its process energy use. In order to reduce process load energy use in the building, a concerted effort has been made by the client to specify low energy use equipment, including EnergyStar rated equipment, in the building. Our strategy had been to collect all of the nameplate energy data available for the equipment, and enter this data into our proposed case model. However, it appears that nameplate data is not the best indicator of actual energy use from equipment. Numerous ASHRAE research projects confirm that nameplate data rarely reflect the actual power consumption of office equipment, and furthermore that the ratio of nameplate to power consumption also varies widely, from 25 to 50% of nameplate for equipment less than 1000W (ASHRAE Research project RP-1005, Hosni et al. 1999). Further plug load reduction strategies being considered include using occupancy sensor controlled power strips, which will allow monitors and other devices to be turned off when the occupants are not present. Proposed Strategy: Actual measured data of power draw from process uses would be the best data to use to model energy use, however this data is not readily available during design. In the rare case where we do have access to the same equipment to that which would be installed in the project, we would propose to measure the power draw from this equipment and use these results for the proposed case model. In most circumstances though, this is not a practical approach. The 2005 ASHRAE Fundamentals Handbook has looked at this issue in regards to how office equipment produces heat, for the purposes of more accurately assessing cooling loads for sizing HVAC systems. In their work, it is assumed that actual power consumption of the equipment is equal to the total radiant plus convective heat gain from the equipment. The Handbook proposes using two different strategies for determining \'actual\' power consumption and heat gain from office equipment (see highlights in attachments). 1. In cases where only nameplate ratings are available, they suggest that ""Generally if the nameplate value is the only information known and no actual heat gain data are available for similar equipment, it is conservative to use 50% of nameplate as heat gain and more nearly correct if 25% of nameplate is used."" 2. Much better results are gained, per the Handbook, by considering heat gains based on the type of equipment. ASHRAE publishes a series of tables in the 2005 Fundamentals Handbook documenting energy rates for multiple types of equipment (Chapter 30, Tables 5 through 10). Note that these tables provide information limited only to certain types of equipment. In regards to occupancy sensor controlled devices, the 2005 California Title 24 energy code allows for a reduction in task lighting energy use of 20% when controlled by occupancy sensors, which is based on their studies of the impact of this technology on energy use. Similarly, we would expect a 20% reduction in energy use for plug loads controlled by occupancy sensors in an office environment. Request: Please confirm that the use of measured power draw data from equipment is acceptable for modeling their process loads, when access to the same equipment is available during design. In cases where this is not available, please confirm that the use of the data published by ASHRAE in case #2 above shall be acceptable for equipment that is covered by their tables, and a factor of 25% used per case #1 for all other cases. If occupancy sensor controlled power strips are used for plug load devices, please confirm that those devices connected to the power strip can be modeled as having a 20% annual power savings. References: 2005 Building Energy Efficiency Standards SECTION 146 - PRESCRIPTIVE REQUIREMENTS FOR SERVICE WATER HEATING SYSTEMS (a) Calculation of Actual Indoor Lighting Power Density. The actual indoor lighting power of the proposed building area is the total watts of all planned permanent and portable lighting systems (including but not limited to, track and flexible lighting systems, lighting that is integral with modular furniture, workstation task lights, portable freestanding lights, lights attached to workstation panels, movable displays and cabinets, and internally illuminated case work for task or display purposes), subject to the following specific requirements and adjustments under Subsections 1 through 6. 4. Reduction of wattage through controls. The controlled watts of any luminaire may be reduced by the number of controlled watts times the applicable factor from TABLE 146-A if: TABLE 146-A LIGHTING POWER ADJUSTMENT FACTORS TYPE OF CONTROL TYPE OF SPACE FACTOR Occupant sensor with ""manual ON"" or bi-level automatic ON combined with multi-level circuitry and switching Any space ?? 250 square feet enclosed by floor-to-ceiling partitions; any size classroom, corridor, conference or waiting room 0.20 2005 ASHRAE HANDBOOK- FUNDAMENTALS page 30.8 to 30.10 Office Equipment - Nameplate vs. Energy Use Table 8 - Recommended Heat Gain for Typical Computer Equipment. Table 9 - Recommended Heat Gain for Laser Printers and Copiers" "The CIR is requesting approval of an Exceptional Calculation Method (ECM) proposed to document the energy savings from selecting energy efficient appliances and equipment to reduce plug loads in the facility. Though the CIR specifically refers to how to calculate the proposed case energy usage, it is equally important to input correct baseline energy usage. In order to claim savings on process load equipment and appliances, actual measured energy use data must be obtained from both the baseline equipment and the proposed equipment. Project teams can conduct these studies themselves or can cite other studies of identical equipment. The same use schedules must be applied to each equipment type in both the baseline and proposed case. ASHRAE 90.1-2004 Appendix G Table G3.2 shows power adjustment percentages for automatic lighting controls. Though this table is not intended to address other systems controlled by occupancy sensors, it would be acceptable to use the 10% power adjustment indicated in the table for buildings greater that 5,000 SF for all systems controlled by occupancy sensors. Alternately, if there is published, credible data available demonstrating energy savings for equipment controlled by occupancy sensors, then the demonstrated values may be used, as long as the study is referenced (or preferably provided). Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1849" "2007-08-13" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "Our LEED project consists of two office buildings of approximately 160,000 sf each plus a central refrigeration plant and parking deck. All buildings will be submitted as one LEED project. The project is currently under construction. The energy model for the project was constructed using Trace700 and is a comprehensive model of all three structures. In addition to the 20% energy savings already being reflected in the model, substantial energy savings will be realized by the investments the Owner has made in advanced energy efficiency measures such as daylighting through a central atrium and interior glazing, raised floor thermodynamics and a hybrid HVAC system. Due to limitations of the Trace700 modeling software, the contributions of these sophisticated energy efficiency measures are not currently reflected in the modeled energy savings. To support the ongoing operations of the building, the Owner has invested in a measurement and verification system, which per EA Credit 5, will include measurement of all electrical power panels, lighting panels broken into interior and exterior lighting, and all hvac equipment. The M&V system will measure and trend demand and consumption of electricity, water and natural gas on an hourly basis for all hours of the year. The project cannot bear the added expense that would be required to perform extensive hand calculations, daylight models or to use more sophisticated energy modeling software, but we would like the Owner to be recognized with LEED points for the contribution that their investment in energy efficient design strategies represents. We would like to incorporate the actual measured performance of the lighting, power, and HVAC systems into the Trace700 model. We propose to delay our LEED application at the end of construction and with all buildings in operation, to measure the building systems performance for 3 to 6 months through the M&V devices. We would then substitute values from the measured performance into the design case energy model. The data would be input on a watt/sqft, kw/cfm, btu/hr, cfh, or gal/min basis. We believe that using measured performance data in the creation of the final design case model would be a cost-effective, accurate means of accounting for the contributions of sophisticated energy efficiency measures, and request permission to use this approach on our project." "The CIR is asking if actual logged energy use data being collected for EAc5 can be used to more accurately represent the proposed building energy use for EAc1, with the caveat that the project certification will be held up until this data has been collected and the energy model has been calibrated. It should be noted that incorporating measured data into an energy model is a strategy fraught with many technical challenges. USGBC encourages project teams to use energy models as a design tool. That said, the proposed technique is acceptable, provided the following conditions are met: [1] One full year\'s worth of energy use data must be included to account for seasonal effects. Additionally, this gives time for the commissioning of the facility to be completed and the ""bugs"" worked out of the system. [2] The collected energy data cannot be directly compared to the baseline modeled energy data. Instead the collected data should be used to populate the inputs to the energy modeling program (ie- plug loads, lighting densities, etc). This is because modeling programs inherently contain assumptions and methodologies that do not directly correspond to actual building energy use. By still running a simulation for the baseline and proposed cases, these discrepancies effectively cancel each other out. [3] The applicant must be able to show that the occupancy schedules, building set points, and intended use of the facility are the same in the baseline and proposed case. [4 The baseline energy simulation must utilize a weather file that represents the same metrological conditions that occurred during collection of the energy use data. [5] Submit all documentation required for an Exceptional Calculation Methodology, as described in ASHRAE 90.1-2004 Appendix G. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1853" "2007-08-13" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our project is a 573,000 SF warehouse facility in a mild climate. The facility is designed to function as a distribution facility at a trucking hub used to store and transfer goods. The typical set-up for a project of this type in the region is to have no mechanical cooling, ventilation and heating (for freeze protection only, temperature set-point 45F) is provided by series of roof-top units with gas-fired furnace. These units are typically constant volume. Since this project is pursuing certification under the LEED-CS v 2.0 rating system, to attempt any points under EA credit 1, we have to follow ASHRAE 90.1-2004, Appendix G - Performance Rating Method. Following the ASHRAE 90.1-2004, Appendix G - Performance Rating Method for a project of this type and size, we will have to model the baseline system as a packaged rooftop VAV with reheat provided by a fossil fuel boiler. A project of this size and type would not have anything even close to this baseline system. Also the modeling protocol requires the project to be modeled with mechanical cooling. Due to the unique nature of the project and its sheer size, it appears that the credit requires the project to use more energy to show that it saves energy. To address this issue, we are proposing the following adjustment to the modeling protocol - Proposed building - Model as designed in terms of envelope, HVAC systems, lighting systems, power distribution and schedules of operations Baseline building - Use the ASHRAE 90.1 section 11 and model as system 11 without mechanical cooling. All other systems will be modeled at minimum required efficiencies as per ASHRAE 90.1-2004. All schedules will be modeled as in the proposed model. Also the outside air rates will be maintained as per the proposed model. We believe that this approach will allow the project to pursue energy efficiency and take credit for any measures that they may apply. We also believe that this variance will allow the integrity of the rating system as it will not require the team to spend extra energy and money to demonstrate achievement of a credit. While the team acknowledges that not all credits apply to all projects, it is very difficult to make a case for green building without demonstrating energy efficiency from the view-point of the owner." "The CIR is asking what to use for proposed and baseline systems to meet the requirements of ASHRAE 90.1-2004 while still fairly representing the warehouse nature of the project. The answer depends on whether the space is classified as conditioned, semi-heated, or unconditioned. As per the ASHRAE 90.1-2004 Users Manual, a space is ""unconditioned"" if it has no cooling and a heating system of less than 3.4 BTUH/SF. A space is considered ""semi-heated"" if it has a heating system with a capacity greater than 3.4 BTUH/SF, but less than the climate specific value that can be looked up on table 3.1 of the ASHRAE 90.1-2004 Standard. If a space contains a cooling system greater than 5.0 BTUH/SF or a heating system greater than that listed in Table 3.1, then it falls in the ""conditioned"" category. The above criteria are based on the total output capacity of the equipment. IF THE SPACE IS UNCONDITIONED OR SEMI-HEATED: ASHRAE 90.1 modeling protocol is based around typical occupied and conditioned buildings. It is not meant to address industrial/manufacturing ""process"" areas, which warehouses may fall under if they meet the requirements of unconditioned or semi-heated spaces. These spaces fall outside the realm of ASHRAE 90.1-2004 and the modeler is asked to include them in the model ""as-is,"" meaning, in this case, including only a heating system and no cooling. The systems should be identical in both the baseline and proposed cases. If the project wishes to show energy savings due to the HVAC system in these areas, an Exceptional Calculation Method (ECM) must be used. See ASHRAE 90.1-2004 G2.5 for this procedure. IF THE SPACE IS CONDITIONED: If the heating provided to the space exceeds the thresholds set forth in Table 3.1 of ASHRAE 90.1-2004, then the standard modeling methodology should be used even if it results in systems that are different than the industry standard for the space type. Please note that typically in a warehouse facility there are some spaces that are fully conditioned (offices, break rooms, etc.). Please follow the standard ASHRAE 90.1-2004 Appendix G protocol for these areas. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1860" "2008-01-30" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "Ours is a project in India wherein we plan to use high efficiency centrifugal chillers. We have a query on fixing the standard COP which needs to be considered in the baseline. As per the ASHRAE 90.1 2004 standard, for centrifugal chillers of capacities more than 300 TR , the baseline efficiencies are selected as per the table 6.8.1C, when tested under ARI 550/590 conditions. For chillers which operate outside the ARI conditions i.e. non standard conditions, ASHRAE 90.1 2004 refers to a sliding chart as per table 6.8.1J given in page 53. This chart also shows a calculation to arrive at K (adj) factor which has to be multiplied with the COP std (i.e. 6.1) to arrive at COP (adj) as per the site conditions. Accordingly, for our project, we have made a detailed calculation. The building would have centrifugal chillers of capacities 400TR, 600TR and 820TR and the operating site conditions are as follows: Leaving chilled water temperature : 44 deg F Entering condenser water temperature : 90 deg F We have arrived at the K (adj) factor based on the calculations shown in page 53 of ASHRAE 90.1 2004 as follows: BASELINE COP CALCULATION FOR CENTRIFUGAL CHILLERS COPadj = Kadj x COPstd Where, COPstd = 6.10 Kadj = 6.1507 - 0.30244(X) + 0.0062692(X)2 - 0.000045595(X)3 X = Condenser DT + Lift Condenser DT = Leaving Condenser Water Temperature (Deg F) - Entering condenser water temperature (Deg F) Lift = Entering Condenser Water temperature (Deg F) - Leaving Chilled Water Temperature (Deg F) X = Condenser DT + Lift = (100 - 90) + (90 - 44) = (10) + (46) = 56 Kadj = 6.1507 - 0.30244(X) + 0.0062692(X)2 - 0.000045595(X)3 = 6.1507 - 0.30244(56) + 0.0062692(56)2 - 0.000045595(56)3 = 0.86 COPadj = Kadj x COPstd = 0.86 x 6.10 = 5.28 NPLV CALCULATION : NPLVadj = Kadj x NPLVstd Where, NPLVstd = 6.40 NPLVadj = Kadj x NPLVstd = 0.86 x 6.40 = 5.50 We need clarification as to whether a COP of 5.28 at 100% load and NPLV of 5.5 can be considered as the basecase efficiencies while carrying out energy simulation for the building." "The applicant requests confirmation regarding their calculation methodology for determining the efficiencies of the Baseline chillers. The calculation methodology provided above is not correct, because it does not take the required operating conditions for the Baseline Case plant equipment into account. Per the requirements of Appendix G, the Baseline Chilled Water Loop shall be modeled with a chilled water design supply temperature of 44 deg. F, and a return water temperature of 56 deg. F (G3.1.3.8); Condenser water shall be 85 deg. F or 10 deg. F approach to design wet-bulb temperature, whichever is lower, with a design temperature rise of 10 deg. F (G3.1.3.11). For a project >= 240,000 square feet, 2 centrifugal chillers minimum shall be modeled with chillers added so that no chiller is larger than 800 tons, all sized equally (G3.1.3.7). These conditions described for the Baseline Case model are standard ARI 550/590 test conditions; therefore, the efficiencies modeled for the Baseline case should reflect the minimum efficiencies given in Table 6.8.1C, and should not reference the values given in Table 6.8.1J. Please note for Energy & Atmosphere Prerequisite 2 (EAp2) that there is also a mandatory requirement within ASHRAE 90.1-2004 that the installed equipment in the proposed design must meet the minimum efficiencies given in the 6.8.1 Tables. The calculation methodology described above is the correct calculation methodology to determine the mandatory performance that the chillers must meet in order to meet for EAp2. Applicable Internationally; India. " "None" "None" "X" "India" "LEED Interpretation" "1876" "2007-09-10" "New Construction" "EAc1: Optimize Energy Performance" "Our project team requests clarification of the applicability of ASHRAE 90.1-1999 section 9.3.1.2 Additional Interior Lighting Power (b) in determining the baseline space by space lighting power densities. In determining energy code compliance, the referenced section allows the values in Table 9.3.1.2 to be increased by up to 0.35 W/ft2 for those spaces where visual display terminals are the primary viewing task and fixtures are installed that meet the detailed luminance at angle criteria. Please confirm that for any space type where visual display terminals are the primary viewing task and the proposed fixtures meet the detailed luminance at angle criteria, the baseline lighting power density shall be the value from Table 9.3.1.2 plus an additional allowance of 0.35 W/ft2 from 9.3.1.2 Additional Interior Lighting Power (b), regardless of the proposed lighting power density." "Per ASHRAE 90.1-1999, section 9.3.1.2 Additional Interior Lighting Power (b), the budget lighting power density is the value from Table 9.3.1.2 plus 0.35 W/sf where visual display terminals are used. The additional 0.35 W/sf only applies to those areas with visual display terminals; spaces without the visual display terminals do not qualify for the additional wattage. The spaces with visual display terminals must also meet the maximum average luminance requirements of this section. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1890" "2007-09-26" "New Construction" "EAc1: Optimize Energy Performance" "This is a LEED NC v2.1 higher education, 240,000-sf student union building located in Washington State. We have provided Radiant Panels to service the heating and cooling loads of general office space. The radiant panels rely on a secondary water loop that supplies either hot or chilled water depending on the demand of the system. Outside air is being provided through operable windows or a dedicated 100% outside air handling unit. After doing some research on several energy modeling programs, we have not been able to find one that can model this approach. Instead, we used a four pipe fan coil unit and zeroed out the fan energy to try and mimic the water loads, but take away the fan motor loads. When we compare the proposed case with the base case for ASHRAE 90.1-1999, the proposed case in the energy model will call for a four pipe fan coil unit (system type 7), which in turn will designate the base case to be a four pipe fan coil system as well. It is our opinion that the base case does not need to be this. For a conventional office space in Washington, the industry standard is to provide a standard rooftop VAV unit and provide each zone with a fan powered terminal with reheat. Also, by using the Budget System Type flow chart in ASHRAE Standard 90.1-1999 and inserting data specific to our project (e.g. water cooled, fossil fuel heating, and non-residential space), we get System Type 2, which is a standard VAV with reheat system. Given this approach, can we use the standard VAV system as a base case for the radiant panels since we are not really using Fan Coils in this system?" "The project team is seeking clarification regarding the appropriate Budget case system type selection for a non-residential building with radiant cooling and heating as its primary source of conditioning. Four pipe fan coils (System type 2) are the appropriate selection for a building with water-cooled chillers and fossil-fuel fired hot water boilers serving radiant panels. Radiant panel systems are generally considered to be single zone systems, since both the heating and cooling panels are located in each zone, and are separately controlled in each zone. Accordingly, the Budget system type would map to Water-cooled ? Single Zone Non-Residential ? Fossil Fuel. Per ASHRAE 90.1-1999 modeling requirements, the fans must be modeled with the same bhp/cfm in both the budget and proposed case (with the exception of savings allowed for premium efficiency motors). Therefore, if the fans from fan coils are modeled with zero power in the budget case, they must be modeled the same in the proposed case. Also, per ASHRAE 90.1-1999 requirements, the dedicated outside air unit providing ventilation to the building must include energy recovery in the budget case if required by Section 6.3.6.1. The project does have the option of pursuing credit for EAc1 using the LEED v2.2 requirements (as long as any submittals for EAp2, EAc2, and EAc6 are also submitted using the LEED v2.2 requirements). This would allow the project to reflect the fan energy savings associated with radiant heating / cooling systems, and to model the Baseline system as a VAV system with hot water reheat as requested in this CIR. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1911" "2007-10-05" "New Construction" "EAc1: Optimize Energy Performance" "Our project has a city zoning requirement for artwork to be installed on our site. The artist that the owner has selected is creating sculptural artwork that incorporates computerized lighting that creates art with lighting. The artwork lighting is programmed to create patterns, colors and movements on site that are not related in any way to pedestrian security lighting or required site lighting. The artwork lighting is also motion controlled to create different patterns depending on how many pedestrians are present on site. Can this artwork lighting be excluded from the EA Credit 1 (Optimize Energy Performance) calculations?" "The CIR is inquiring as to whether the energy use from the lighting for on-site artwork needs to be included in the EAc1 calculation. This energy use falls under the ""process load"" classification, and needs to be included in the energy model if it generates internal heat gains or interacts with other energy systems, as per the LEED-NC v2.1 Reference Guide. In this particular case, the CIR wording implies that the artwork is outside and thus the lighting should not contribute to HVAC equipment loads. Also the lighting is specifically intended for artistic effect and therefore can be excluded from the exterior site lighting requirements based on ASHRAE 90.1-1999 Section 9.3.2 Exception (b). Assuming there are no additional interactions with building energy systems, this energy usage can be excluded from the EAc1 calculations. Please note, this lighting would still need to comply with the requirements of Sustainable Sites Credit 8, if attempted." "None" "None" "LEED Interpretation" "1915" "2007-10-24" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The purpose of this CIR is to obtain confirmation of what is considered New Buildings vs. Existing Building Renovations within Option 1 of this credit. The project consists of a 120,000 SF existing building, which is part of and connected to other buildings in a corporate campus. The building was recently used for offices, which is the predominate use of the campus. There is no central mechanical plant for the campus-each building has its own mechanical system. The building is being converted to a large data center. The building\'s exterior shell will be retained but the existing mechanical and electrical systems, as well as all interior partitions, ceilings and finishes, will be removed. In short, the building is being gutted. We will be submitting this credit under Option 1: Whole Building Energy Simulation. The mechanical engineer is confident that the building will save at least 7% energy costs but not sure it will achieve 14%. Since we are required to achieve 2 points in this credit to achieve certification, we wish to be certain that the project will be considered Existing Building Renovation for the purpose of awarding points for energy savings." "Because the existing building shell is preserved, this project can apply for EAc1 using the Existing Building Renovations energy cost savings thresholds. Please note that if there are portions of the project that will be new construction, then use the equation provided in the LEED-NC v2.1 CIR Ruling dated 9/5/2001 (and revised on 9/21/06) to determine the appropriate point-thresholds. The equation follows below: To calculate the optimization point table for a project that has both existing and new construction, use the following formula for each line of the table: target percent = (existing SF / total SF) * (existing percent) + (new SF / total SF) * (new percent) Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1928" "2007-10-23" "New Construction" "EAc1: Optimize Energy Performance" "The intention of credit EA c1 is to demonstrate an increased level of energy performance above the base line established for EA Prerequisite 2. Following Option 1 we are creating a Whole Building Energy Simulation of our project (a high rise residential development) using DOE-2 software. Among a number of significant energy-saving strategies the design team proposes the following:  A manual master switch control located at the entrance door to each apartment will allow the occupant to turn off all the lighting in the apartment (including switched outlets) upon exit. This is similar to the strategy for hotel rooms addressed in a CIR of 5/14/07 where a central switch controlling lighting in hotel rooms was allowed to contribute to credit fulfillment as an Exceptional Calculation Measure.  The same control that turns off the lighting will also bring the HVAC control for the residence make-up air supply and exhaust system to an unoccupied mode and thus reduce the amount of ventilation air being supplied to empty apartments. This will reduce the energy used by fans supplying the air and reduce the heating and cooling loads applied to that air volume. This is similar to the strategy for energy use reduction commonly used in commercial buildings where less outside air is delivered on a scheduled basis (late at night or weekends). The majority of apartments in this building will be not the primary residence of the occupant. In fact the owner projects that typical occupancy will be at 60% compared to a situation where the apartments are the primary residence. Therefore the energy savings that can be demonstrated due to the controlled reduction in lighting and air flow are substantial. Is the above strategy acceptable for contribution to Credit EA 1?" "The strategy to use a manual master switch control in each apartment to turn-off lights and control the HVAC system in response to occupancy does not qualify for credit under EAc1. Manual controls are not eligible for credit. An automated control system (such as the strategy in the referenced CIR) would be eligible for credit. The amount of energy savings from an automated system would need to be supported by citing a relevant research study. However, the strategy of using manual master switch controls for each apartment may be eligible for an Innovation in Design credit. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1931" "2007-10-23" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is an existing landmarked building in NYC pursuing LEED Core & Shell certification. Specifically, the building will undergo a gut rehab of all its floors. The building is currently served by four CFC chillers. To increase the energy efficiency of the building, and to obtain the two EAc1 points, the building plans to replace the CFC chillers with efficient chillers that also comply with the requirements of EAc4 Enhanced Refrigerant Management. Energy modeling projects that chiller replacement will result in $48,200/year energy cost savings. The cost of replacing chillers is high, because piping and ducting added over the years to the mechanical room are making the removal of the chillers impossible without changes to the MER. The cost of replacement including changes that would be needed for piping, controls and modifications to existing mechanical room is estimated to be 4-5 million dollars, resulting in a simple-payback above 80 years. Under LEED-EB, the Ozone protection prerequisite recognizes that if replacing chillers is not economically feasible, or if the simple-payback of the replacement is greater than 10 years, an alternate compliance path would be acceptable. The path recommended is that the CFC-based refrigerants be maintained, and the annual leakage be reduced to 5 percent for the life of the units (the requirements for LEED-EB). We believe that this indicates that flexibility can be granted when economic conditions are adverse, and would like to propose that such flexibility to granted to the LEED CS EAc1 in this particular case. Chiller replacement in this building is not economically feasible, but the owner has committed nonetheless to phase in new chillers over the period of 5 years. The 5-year period is primarily due to the large economic burden required by a replacement that does not have a reasonable payback. Computer modeling projects that with this replacement the Core & Shell will meet the 2 credit requirement for EAc1. We propose that replacing the chillers over 5 years is much better than retaining the current chillers, both for energy use and for ozone-depletion reasons - even with care for CFC leakage. With the owners committed to phasing in the new non-CFC chillers within 5 years, will this be acceptable to use the new, planned chillers for meeting the 2 point requirement for EAc1?" "Phasing in of new, non-CFC chillers within 5 years appears to meet the intent of EA prerequisite 3 on Fundamental Refrigerant Management. Prior to phase-out, the annual leakage of CFC-based refrigerants must be reduced to 5% or less using EPA Clean Air Act, Title VI, Rule 608 procedures governing refrigerant management and reporting. EAc1, Energy Performance Optimization, should not include the future chillers. This is covered by Appendix G, section G1.3 (p.169), which states that parameters relating to future components shall be identical in determining the baseline and proposed building performance. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1946" "2007-11-19" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our project is a new-construction library building, in a northern climate, with 5-stories underground (below grade) and 1 story above ground with a dome-shaped glass wall/roof structure. The glass dome is egg-shape in design (if the egg were on its side half buried in the ground), and encompasses one floor of occupied circulation and office space. The 5-stories underground will serve as climate-controlled mechanized book storage and retrieval, with little regularly occupied space. The project is designed and located to be in good standing for LEED certification, though the glass wall/roof design creates some questions about obtaining the minimum of 2 credits under EA Credit 1. We have spoken with a USGBC representative who recommended that we consider the three following assumptions when we compare the baseline energy model to the design case model. We would like to clarify whether these assumptions are correct with regard to building compliant energy models for this project. 1) The underground 5-stories of the building will be primarily climate controlled book storage, which we feel is a very energy efficient approach to design. We assume that for the energy model, our baseline building will be an above ground building (6 stories total) with typical wall construction. 2) The glass dome structure that serves as the ground floor walls and roof has clear viewing fenestration from grade to 14 feet. The dome is a total of 35\' tall. None of the fenestration is ""vertical"" glazing, it is at an angle that would deem it a skylight under a strict interpretation of ASHRAE 90.1-2004, though the dome is serving as a combined roof and wall structure. We propose treating the first 14 vertical feet of glazing as wall area (with 100% glazing according to ASHRAE 90.1-2004) in the design-case energy model, and the remaining vertical feet of dome area (from 14\' to 35\') as skylight (100% skylight, according to ASHRAE 90.1-2004) in the design-case energy model. 3) If the first 14 vertical feet of glass is treated as wall area in the design-case model, it would then represent a given percentage of wall glazing in the baseline energy model (represented as an above-ground building). To achieve a 14% improvement in the performance of the designed building, the design-case energy model will still be challenged by the ASHRAE 90.1-2004 allowance of a maximum 5% skylight area on the baseline energy model -against which we will be comparing our design-case model that has 100% of the roof area as a skylight. To summarize, this project is in good standing for LEED certification but we require clarification on our assumption that the baseline-case building would be an above-ground structure, that the first 14\' vertical feet of angled dome fenestration be treated as wall area in the design-case model, and that this respective area of fenestration would be used as wall glazing on the baseline model." "The applicant is seeking a variance in the manner in which the baseline and proposed buildings can be modeled for a very specific design condition. The following responses address the numbered items in the request. 1. The proposed approach is not acceptable. Please note that the modeling methodology used for this credit is not intended to be used solely to demonstrate compliance, but rather to reward significantly better performance. It is therefore an unfair comparison to model the baseline completely above grade. The below grade wall should be the same in both the baseline and design cases. Comparing the design case to an above grade baseline is not acceptable per the modeling protocol. To demonstrate better envelope performance than that prescribed by ASHRAE 90.1-2004, it is important that the design team make necessary modifications to the proposed envelope design. 2. & 3. Your suggested approach is acceptable. Please note that the baseline model will only have 5% of the roof area as skylight. The applicant must provide surface area calculations in a narrative format to demonstrate that the total area of wall plus roof is identical in both the models." "None" "None" "LEED Interpretation" "1980" "2007-12-18" "New Construction" "EAc1: Optimize Energy Performance" "Office occupancy primarily consists of the use of a building for the transaction of business or for similar purposes, which is consistent with the operations of a branch bank. We are proposing that commonalities include hours of operation, mechanical systems, lighting types and levels, furnishings, finishes, equipment, and daily internal occupant activities. This building, located in Marana, Arizona, falls under the IBC 2006. According to IBC 2006 Sec. 304.1: Business group B occupancy includes, among others, the use of a building or structure, or a portion thereof, for office, professional or service-type transactions, including storage of records and accounts. Business occupancies shall include, but not be limited to, the following: Airport traffic control towers Animal hospitals, kennels and pounds Banks Barber and beauty shops Car wash Civic administration Clinic-outpatient Dry cleaning and laundries; pick up and delivery stations and self-service Educational occupancies above the 12th grade Electronic data processing Laboratories; testing and research Motor vehicle showrooms Post offices Print shops Professional services (architects, attorneys, dentists, physicians, engineers, etc.) Radio and television stations Telephone exchanges According to IBC 2006 Sec. 309.1: Retail stores fall under the Mercantile Group M occupancy, which includes, among others, buildings and structures or a portion thereof, for the display and sale of merchandise, and involves stocks of goods, wares or merchandise incidental to such purposes and accessible to the public. Request: As the IBC considers banks and retail establishments to be separate occupancy classifications, and that banks are consistent with ""office, professional or service-type transactions,"" we propose that a branch bank building be considered office occupancy and therefore eligible for evaluation under the measures of ASHRAE Advanced Energy Design Guide for Small Office Buildings 2004, provided it meets the square footage requirement of the measure (under 20,000 s.f.)." "The applicant is requesting reclassification of a branch bank from retail to office occupancy. Occupancy type reclassification for code and related purposes is out of the purview of a Credit Interpretation Request. However, for the purposes of LEED" "None" "None" "X" "LEED Interpretation" "2028" "2008-01-29" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Background: The Eastside Recycling center in Iowa City, IA will be a campus of 10 buildings / structures owned by the City of Iowa City. These buildings will provide public facilities for post-consumer recycling, materials re-use and sustainability education. As part of this campus, there will be 4 pre-engineered metal buildings. Each will be used for storage of recycled materials, electronic waste, materials to be re-used, and other miscellaneous storage. Only one of the 4 pre-engineered metal buildings has a dedicated office space which will be located in one corner of the building. The campus of buildings will be LEED certified using the LEED-NC for Multiple Buildings and On-Campus Building Projects. It is our intent to include these 4 pre-engineered buildings as part of the LEED certification. Proposed Strategy: In order to reduce energy consumption and simplify building maintenance, these 4 pre-engineered buildings will not be conditioned. Each building will have dedicated large-diameter overhead fans to circulate air, but there will not be a dedicated heating or cooling system. There will be a small office space in one of the metal buildings which will have an operable window as well as an electrical service outlet for a fan in the summer or electric space heater in the winter. These buildings would be defined by ASHRAE 90.1 as an unconditioned space, having less than 3.4 Btu/h*ft2 of floor area (both heating and cooling). As such, these buildings would not fall under the envelope requirements of ASHRAE 90.1. The minimum energy efficiency standards for EA Prerequisite 2 must comply with ASHRAE 90.1, and the performance rating calculations (using a whole building project simulation) for EA Credit 1 must comply with the Building Performance Rating Method in Appendix G of ASHRAE 90.1-2004. Because ASHRAE 90.1 does not apply to envelopes of buildings that are unconditioned space, the 4 pre-engineered buildings do not fall within the requirements of this standard. It is proposed to exclude the 4 pre-engineered buildings in the composite campus energy performance calculations in EA Credit 1 (Option 1) for the group of buildings to be LEED certified. As such, these 4 pre-engineered buildings would be excluded from the minimum energy efficiency levels required by EA Prerequisite 2. Interpretation: Is it acceptable to exclude these 4 pre-engineered buildings from the minimum level of energy efficiency requirements in EA Prerequisite 2 and the building performance rating calculations for EA Credit 1 (OPTION 1)?" "The applicant requests clarification regarding whether unconditioned buildings may be excluded from the energy efficiency prerequisite (EAp2) and the energy efficiency performance rating calculations for EA Credit 1. If the buildings are included as part of the LEED scope of work, then they must be included in the energy calculations for EA Credit 1, and must meet the applicable portions of the referenced standard for EAp2. Specifically, the lighting for these buildings must comply with the minimum requirements of ASHRAE 90.1-2004. For EAc1, these buildings would be treated very similarly to unconditioned parking garages, where the envelope does not necessarily need to be modeled, but the electric loads from the lighting and fans are included in the energy calculations. Lighting in the baseline case should be consistent with the interior lighting power allowance in Section 9.2. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2030" "2008-03-04" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is a large mixed use complex which will include a high rise residential tower, a mid rise hotel, a theater, retail base under each of the above 3 buildings and parking facilities associated with all of the above. There are several energy saving measures being considered for systems which are not addressed in ASHRAE 90.1-2004 prescriptive requirements or appendix G. Please advise if the proposed approach to modeling is acceptable. 1. The high rise residential tower includes provisions for individual clothes dryers in each apartment. Thus the building will include engineered dryer exhaust systems to serve the stacked clothes dryers. In accordance with manufacturers recommendations and good engineering practice, the exhaust systems will be sized based on a 60% diversity factor to be able to function during periods of high usage. Typically such systems are constant volume systems that exhaust air continuously, even when most of the dryers are off. We are proposing to use a variable volume system which will modulate the fan speed to maintain the recommended pressure in the riser at all times. This will substantially reduce fan energy and also reduce the required make-up air heating and cooling costs, since the make-up air unit will be VAV and reduce volume in proportion to the reduction in dryer exhaust volume. ASHRAE 90.1 - 2004 does not address requirements for such systems therefore we believe it is justified to model the baseline system as constant volume exhaust with corresponding constant volume make-up air. The make-up air unit also includes capacity to match the toilet exhaust. However the toilet exhaust is less than the dryer exhaust and makes up only about 40% of total exhaust. We propose to provide heat recovery from the toilet exhaust to the make-up air. We believe that the baseline model can be set up without heat recovery from the toilet exhaust based on the fact that the system meets exception 6.5.6.1 (h) where the largest exhaust source is less than 75% of the design outdoor airflow and thus is not required to have heat recovery. 2. The lower level parking garage is classified as enclosed and thus mechanically ventilated. The parking garage serves the hotel and residential building and thus will be in use 24 hours a day. We are proposing to provide a system of carbon monoxide sensors and associated controls to operate the ventilation for areas of the garage only as needed to maintain" "Three proposed modeling approaches have been described in this request. 1. The project team proposes to model the baseline case toilet exhaust without heat recovery. This approach is not acceptable. Sub-section (f) under ASHRAE 90.1-2004 Section G3.1.2.10 (f) states that ""this exception shall only be used if exhaust air recovery is not used in the proposed design."" While Section 6.5 is a mandatory section for the purposes of meeting EAp2; modeling guidelines should be followed as per ASHRAE 90.1-2004, Appendix G. 2. The project team proposes modeling the parking garage ventilation system as variable, dependent on carbon monoxide sensor readings and the baseline case as constant. This is acceptable, but should be modeled as an exceptional calculation method if automatic controls cannot be explicitly modeled using the approved energy modeling software. Documentation must be provided that supports the savings and assumptions made if using an Exceptional Calculation Method. Please refer to ASHRAE 90.1-2004 Section G2.5 for further guidance. 3. The project team proposes that heat recovery does not have to be modeled in the baseline case for a central boiler plant/transformer vault ventilation system. This approach is acceptable, given that the air is tempered to 50" "None" "None" "X" "LEED Interpretation" "2039" "2008-03-04" "New Construction" "EAc1: Optimize Energy Performance" "We are modeling a solid waste transfer station facility and a materials recovery facility for the South Bayside Waste Management Authority in San Carlos, CA. The two facilities for the project are unconditioned spaces; they are not heated or cooled. In regard to the ASHRAE 90.1 modeling parameters under Energy and Atmosphere Credit 1, where heating and cooling systems are required to be modeled for both the proposed and baseline models (even when such systems do not exist) we propose to use two strategies to most accurately represent our facility and comply with the accepted procedure for modeling. Firstly, we propose to model the thermostat set points such that those systems are not activated. For example, with a cooling set point of 95 degrees F, the cooling equipment will remain idle and no energy use will be modeled. ASHRAE 90.1 does not specify where thermostat set points should be set; it only requires that the set points be the same for the proposed and baseline models. Setting them such that the equipment is not activated will accurately measure the energy use, since no heating and cooling will be provided for the facilities and therefore no energy will be used for heating and cooling. We feel this method meets the intent of the credit, since no heating or cooling system could possibly use less energy than we propose to use. Is this acceptable? Secondly , the materials recovery facility contains a small number of people in relation to the square footage of the building. These occupants will all work in a localized area along the production lines that sort the solid waste stream. If we provide spot cooling and heating for the comfort of these workers, we propose the energy used by these systems be modeled as process energy. Heating and cooling systems for this purpose will not be used to heat or cool the space, but to provide comfort for the workers on the line by immersing them in an airstream that is cooler or warmer than the ambient conditions. These systems will be idle when workers are not present and will not be capable of maintaining a thermostat set point in the whole of the large, mostly unoccupied footprint of the building. As process loads, the systems will be modeled to operate on the same schedule as other process equipment, such as conveyors and sorting machinery. Is this methodology allowable?" "The first strategy discussed by the project team proposes modeling setpoints in unconditioned spaces so that the system is not activated in order to meet the requirements of ASHRAE 90.1.2004 Table G3.1 #10 and yet model the actual system characteristics. This approach is acceptable, given that the systems are modeled identically in both the proposed and baseline cases. However, for conditioned spaces (see sub-zone suggestion below), the setpoints should be modeled to accurately represent the conditions in the space. The second question proposes that personal/localized cooling and heating systems are represented as process energy rather than HVAC energy. This approach is not acceptable for the achievement of this credit. ASHRAE 90.1-2004 defines process energy as ""energy consumed in support of a manufacturing, industrial, or commercial process other than conditioning spaces and maintaining comfort and amenities for the occupants of a building"" (see Definitions). The project team might consider creating a conditioned sub-zone for the localized area that mimics as closely as possible the spot heating and cooling provided (in terms of setpoints, air temperature and/or ventilation rates), based on guidance provided in ASHRAE 90.1.2004 Table G3.1 #13. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2042" "2008-03-04" "New Construction" "EAc1: Optimize Energy Performance" "The project consists of four interconnected laboratory buildings as part of a university science complex in Allston MA. The buildings are new construction, with 5-7 story structures, primarily steel and concrete materials consisting of approximately 1,000,000 square feet. The Option 1 (Whole Building Energy Simulation) for this credit requires a demonstration of a percentage improvement in the proposed building energy performance compared to the baseline energy performance found in ASHRAE 90.1 - 2004 Appendix G. The baseline modeling requirements of the ASHRAE 90.1 system are appropriate for office buildings but the unique characteristics of a lab create certain conflicts with the ASHRAE 90.1 system. They are as follows: - While the standard provides pressure credits for filtering systems, heat recovery, etc., laboratory fan systems typically exceed the fan limitations even with these credits due to other components. - Conflicts with minimum airflow in standard and laboratory minimum ventilation rates both occupied and unoccupied. - Schedules of equipment operation are different than in the ASHRAE baseline. - Additional conflicts with the application of the standard to labs are identified in the Labs21 modeling guidelines. Proposed Modeling Strategy The design team is proposing the use of ""Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G"" produced by Laboratories for the 21st Century, or Labs21. A joint venture of the Environmental Protection Agency and the Department of Energy, Labs21 has enlisted some of the biggest laboratory operators in an effort to corral energy consumption and cut attendant costs. Participating labs are saving up to 30-50 percent on their energy bills compared with those not using the program. The guideline describes an appropriate baseline model for energy benchmark simulations using ASHRAE 90.1-2004 including proposed corrections (http://www.labs21century.gov/pdf/ashrae_appg_draft_508.pdf). Although proposed use of this standard was previously not accepted by the USGBC in the CIR dated 5/11/2005, the USGBC\'s LEED for Laboratories Application Guide (Draft) clearly acknowledges the issues with the ASHRAE standard and therefore, under Requirement 1 for Energy and Atmosphere, states ""the building project is to comply with.the requirements of the Labs21 Laboratory Modeling Guidelines using ASHRAE 90.1 - 2004."" The various proposals of the Labs 21 Committee have been included in the continuous maintenance efforts of ASHRAE and modifications continue. Some of the revisions are under public review (addenda o and r) and some are already accepted addenda (e.g. addendum ac - fan power for laboratory type zones). Additionally, this standard has been approved by the State of Massachusetts for use as the base case. Per the memorandum published by the USGBC in April 26 2007, ""LEED project teams are required to use the ASHRAE Standard referenced in the applicable Reference Guide and are permitted to use addenda within the most recent Supplement to that Standard, as well as any approved addenda published in between the eighteen-month periods."" Request Please confirm that using the Labs21 ""Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G"" is acceptable when recommendations of the Labs21 have not already been implemented by ASHRAE 90.1 energy modeling baseline. For all items covered in Labs21 that have been addressed by ASHRAE amendment, we will use the ASHRAE requirements." "Project teams may not use the Labs21 ""Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G"" as a compliance path for modeling laboratories. The deficiencies in modeling laboratories are being addressed through addenda to ASHRAE 90.1-2004. Project teams are permitted to use addenda to ASHRAE standards as outlined in a USGBC Memo posted here: http://www.usgbc.org/ShowFile.aspx?DocumentID=2664. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2047" "2008-03-04" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "ENERGY & ATMOSPHERE: Minimum Energy Performance (EAp20) 4/30/2005 - Credit Interpretation Request The Saranac is a renovation and historic preservation of a 4 story hotel. The building will be converted into a multi-use facility that will include housing, offices, symposium space, theater and restaurant uses. The building is designated as a contributing structure to the Downtown Spokane National Historic district. the building is also on the local Historic Register and is subject to review of the local Landmark Commission. The design restrictions will result in restoring the storefront and primary elevations to 1900 era appearance. In our case the entire building will be renovated but the esterior appearance of the building will remain largely unchange with the exception of the addition of exterior sun shades on the non-primary elevations. The building systems will be replaced. Can the buildings existing envelope chariteristics be used to extablish the energy usage baseline per ASHRAE 90.1 (Section 4.1.2.2)? 5/23/2005 - Ruling Yes. As established in the EAp2 CIR Ruling dated 3-11-03 and ASHRAE 90.1 Sections 4.1.2.2, the historical facade is exempt from minimum energy performance. Section 11.4.2 also states ""for existing buildings, the budget building design shall reflect existing conditions prior to any revisions that are part of this permit."" _________________________________ Based upon this CIR I have a question about our current project, the renovation of an existing mill building into spec office space. Please note that the mill building is ""specifically designated as historically significant by the adopting authority or is listed in \'The National Register of Historic Places\' or has been determined to be eligible for listing by the US Secretary of the Interior"" per ASHRAE 4.2.1.3. I would like to confirm the following: 1. This CIR which was filed for a New Construction project applies to a Core and Shell project. Please confirm. 2. We believe this CIR allows us to use the original facade/envelope conditions to set our minimum energy performance as required for EA Prerequisite 2. Please confirm. 3. We believe this CIR allows us to run our energy model using the original facade/envelope design conditions to set the baseline for energy model comparison with the renovated facade/envelope design. Please confirm. 4. When we compare the original envelope against the renovated envelope (which can only consist of new windows and added roof insulation per the Historic Registry guidelines) our energy performance, based upon cost, increases by 23%. -We believe that this means we meet EA Prerequisite 2. Please confirm. -We also believe that under credit EA-1 we would qualify for 6 points as this is an Existing Building Renovation. Please confirm." "Based on the information provided, it appears that the requirements for EAp2 have been met and if this project achieves 23% savings in energy, incumbent on verification of documentation submitted during the review process, it would qualify for 6 points for an existing building renovation. In response to the questions raised: 1. This particular CIR, which was filed for a New Construction project, can be applied to a Core and Shell project. 2. Yes, the referenced CIR and ASHRAE 90.1-2004 Section 4.2.1.3 Exception (a) allows the project to meet the minimum energy performance requirements of EAp2. 3. This issue is unrelated to the original CIR, but the approach is acceptable under the requirements of ASHRAE 90.1-2004 Table G3.1 No. 5, (f) under Baseline Building Performance, which states that ""for existing building envelopes, the baseline building design shall reflect existing conditions prior to any revisions that are part of the scope of work being evaluated."" Applicable Internationally\n" "None" "None" "X" "LEED Interpretation" "2048" "2008-03-04" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "This project is seeking a single LEED-CS certification for 12 free standing structures in close proximity at a single retail outlet shopping mall. Per ASHRAE 90.1-App. G protocol, each structure will be modeled individually to accurately represent the thermal envelope and building orientation comparisons. When inputting information into the EA credit-1 online template, should the energy performance for all twelve buildings be totaled and input as a single amount for both baseline and proposed (i.e. will a single EA template input be allowed by adding the energy model performance of each structure to reach a total for input on the template)? The alternative would be treating each structure individually (12 EA template inputs) and averaging all energy performance differentials to determine the total project EA credit." "The project team is requesting confirmation on submitting the energy performance information for 12 free-standing structures. USGBC has an application guide for LEED-NC projects submitting multiple buildings in one application (http://www.usgbc.org/ShowFile.aspx?DocumentID=1097). This guidance can be used by Core and Shell projects when applicable. For EAc1, you may input the data for all buildings into one template. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "2049" "2008-03-04" "New Construction" "EAc1: Optimize Energy Performance" "Our project consists of adding a new 5,000 square foot education building addition to an existing 17,500 square foot education building. The original building was not submitted for LEED certification but we are submitting for LEED certification on the new addition. The original project was constructed with a complete four pipe hydronic system including chillers, pumps, and boilers that have the capacity to handle the new addition with no added plant capacity. The scope of this project is to provide new air handling equipment and extend the existing four pipe hydronic distribution system to the new air handling equipment. Our approach to satisfying the newly established mandatory 14% energy efficiency improvement is outlined as follows: A base case model was established by using the criteria set by ASHRAE Standard 90.1-2004, Energy Standard for Buildings except Low Rise Residential Buildings. The minimum requirements established for this model are as follows: -Walls: Mass Assembly with U-value = 0.58 Btu/hr.ft2-" "In requesting clarification on the proposed modeling methodology, it is unclear, based on the information provided, whether the project team is modeling the existing building as well as the addition. From ASHRAE Table G3.1 #2, the project will not meet all of the conditions to exclude parts of the existing building, as the requirements of (b) are not satisfied. Therefore, the project team must model the entire building, taking care to follow the requirements of Table G3.1. This includes #5, where the existing envelope must be modeled equally for the proposed and baseline cases, as well as the HVAC Systems requirements in #10. Please note that #10 portion (a) states that when an existing HVAC system exists, the proposed model shall reflect the actual system type, etc." "None" "None" "LEED Interpretation" "2078" "2008-04-23" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is a large mixed use complex which will include a high rise residential tower, a mid rise hotel, a theatre, retail base under each of the above 3 buildings and parking facilities associated with all of the above. The following important energy saving measures is being considered for a system which is not addressed in ASHRAE 90.1-2004 prescriptive requirements or appendix G. Please advise if the proposed approach to modeling is acceptable. 1. The high rise residential tower includes provisions for individual clothes dryers in each apartment and will include engineered dryer exhaust systems to serve the stacked clothes dryers. In accordance with manufacturer\'s recommendations and good engineering practice, the exhaust systems will be sized based on a 60% diversity factor to be able to function during periods of high usage. Typically such systems are constant volume systems that exhaust air continuously, even when most of the dryers are off. We are proposing to use a variable volume exhaust system which will modulate the fan speed to maintain the recommended pressure in the riser at all times. We are also proposing to use a variable volume make-up air system which will vary the make-up air volume to match the exhaust flow rate. Both systems will substantially reduce fan energy and also reduce the required make-up air heating and cooling costs. ASHRAE 90.1 - 2004 does not address requirements for such dryer exhaust systems therefore we believe it is justified to model the baseline system as constant volume dryer exhaust with constant volume make-up air system. The proposed design will reflect the discussion above and be modeled as variable volume exhaust with variable volume recovery. Neither the baseline nor proposed design will include heat recovery because applicable codes prohibit any obstruction in the dryer exhaust systems. Please confirm whether modeling the baseline as constant volume exhaust and constant make-up without heat recovery and the proposed design as variable volume exhaust and variable volume make-up air without heat recovery is an acceptable modeling approach." "The project team is requesting verification of whether a variable volume exhaust system and variable volume make-up air system for stacked dryers in a residential building can be compared to a constant volume exhaust system in the Baseline energy model. As indicated by the project team, this issue is not addressed in ASHRAE 90.1-2004 prescriptive requirements or in Appendix G. Credit for systems not specifically addressed in the Appendix G modeling methodology must be modeled using the Exceptional Calculation Method, and theoretical and/or empirical information supporting the accuracy of the calculation method must be included. If the project submits an Exceptional Calculation Method to document credit for variable volume exhaust system and variable volume make-up air system for stacked dryers, they would need to clearly document: 1. That the Baseline system defined (including both the constant volume controls and fan capacities) is consistent with standard practice for similarly sized, newly constructed high-rise residential buildings. 2. How the control sequences will be applied to the project to achieve a true reduction in make-up air and exhaust-air volume during periods of low dryer usage (it is unclear how the pressure in the riser will correlate to the quantity of dryers in use, or how the makeup air and exhaust air volumes will be tracked with one another). Applicable Internationally." "None" "None" "X" "LEED Interpretation" "2081" "2008-04-25" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "Recently, USGBC approved a CIR regarding savings from key cards in hotel rooms (5/14/07 - see attached). We are requesting that under LEED-NC savings from submetering of multi-family buildings be accepted as an exceptional calculation method. There are no code requirements for submetering of apartment or condominiums in multi-family buildings. Submetering of utilities for individual tenants or owners in multi-family buildings is an added construction cost, but significant energy savings result. Studies have shown that a minimum of 10% energy savings are achieved once individual metering is implemented. Research done by the New York State Energy Research and Development Authority (NYSERDA: http://www.nyserda.org/publications/SubmeterManual.pdf) estimates that installing sub-meters in a master-metered building can reduce building-wide electricity consumption by 10-26%. In Ontario, Canada, non-electrically heated submetered apartments have shown a 16-22% reduction in electricity consumption while electrically heated apartments with submetering showed a reduction in consumption of 30% (http://www.frpo.org/Document/Topics&Issues/UtilitiesEnergy/Options%20to%20Reduce%20Energy%20Consumption%20by%20Encouraging%20Sub-Metering%20and%20Individual%20Billing%20in%20Multi-Residential%20Rental%20Dwellings.%20By%20FRPO,%20February%202003.pdf). Based on these studies and the fact that submetering is not required by the energy codes, we request that USGBC allow an exceptional calculation method to account for the savings from submetering. We are proposing that 10% cost savings of all submetered end uses be allowed by the calculation method. So, if a living unit is submetered for electricity and gas, the project can assume 10% cost savings for each of these fuel sources based on the energy use within the unit. Energy use in common areas of the building would be excluded from the calculation. Is this acceptable? Related CIR\'s 4/12/2007 - Credit Interpretation Request Per ASHRAE 90.1-1999 and 2004 mandatory requirements, hotel guestrooms must include a master control device at the main room entry that controls all permanently installed luminaires and switched receptacles. We are considering automating this lighting control with the use of a key card-activated master switch. The control would turn off all permanently installed and switched receptacle lighting after the guestroom is unoccupied for more than 30 minutes. The controls may also be configured to allow the interior window shades to be closed automatically when the guestroom is unoccupied. Monitored data for hotel lighting usage patterns is provided in a 1999 Research study by Erik Page and Michael Siminovitch entitled ""Lighting Energy Savings in Hotel Guestrooms."" This study indicates an average daily usage of nearly 8 hours for the bathroom light, 2 hours for the desk table lamp, 5 hours for the bedside lamp, and 3 hours for a floor lamp. The study also showed that the high use fixtures (the bathroom fixture and bed lamp) did not experience a significant drop during typically unoccupied periods. Instead, these lights were 20% - 25% on during these periods; and the lighting energy consumed during these periods accounted for about 60% of the total guestroom lighting energy consumption. Another study for ACEEE entitled the ""Emerging Energy-Savings Technologies and Practices for the Building Sector as of 2004"" projects an energy savings for key card lighting controls of 30%. Based on the information provided in these two studies, it seems reasonable to credit hotel guestroom lighting fixtures with a 30% energy savings for automated control based on room occupancy. We propose to model the energy savings achieved through automated control of lighting and interior window shades as an exceptional calculation measure. The lighting savings would be calculated by adjusting the proposed case lighting schedules for all permanently installed and switched receptacle fixtures to 50% lower than the budget case for the percentage of guestrooms modeled as unoccupied. Lighting during all occupied periods will be modeled identically to the budget case. The guestroom lighting energy savings achieved through this measure for the affected lighting fixtures would be 30%. Automated control of the blinds is intended to limit solar heat gains, since the building is in a hot dry climate. The blinds will be modeled identically during the occupied periods as 50% open during daylit hours, and 25% open during evening hours. During unoccupied periods, the shades will be modeled as 25% open. As with all exceptional calculation measures, the savings for this automated control measure will include a narrative documenting the lighting and interior shading schedules and assumptions, and the calculation methodology, and will include a separate line item on the ECB report documenting the savings achieved from this measure. We would like confirmation whether the proposed modeling methodology is acceptable, or direction regarding any modifications that would need to be made to the proposed modeling methodology in order to comply with LEED ECB modeling requirements. 5/14/2007 - Ruling The applicant is requesting confirmation on the proposed strategy for two exceptional calculations. Based on the description of the lighting assumptions, the proposed approach is acceptable. In the LEED submittal please include a narrative documenting the lighting schedules and assumptions and the calculation methodology. Also include a separate line item on the ECB report documenting the savings achieved from this measure. Please provide enough detail in the documentation to allow the review team to ascertain the amount of credit claimed. Based on the description of the automated blinds, the assumptions concerning blind control are insufficient to model the proposed building." "The project team is inquiring as to whether or not sub-metering of multi-family residential buildings would be acceptable as an exceptional calculation method. The energy savings associated with sub-metering are due to a change in occupant behavior and not due to building efficiency. As a result, the schedules in the baseline case must be modeled identically to those in the design case. Therefore project teams may not claim credit for sub-metering of a multi-family residential building through the exceptional calculation method." "None" "None" "LEED Interpretation" "2086" "2008-04-23" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "This CIR is in regards to a 22,000 sf pool addition to an existing high school in upper climate zone 6. The building will contain a high-school sized short course pool in addition to a small therapy pool as well as locker rooms and two small offices and storage areas. The building\'s footprint is approximately square in shape and glazing will be used around the majority of the pool area to allow daylighting. The lighting system in the main area will have three levels of control to adjust for natural daylight to pour in and thus the lighting can be reduced appropriately. For compliance with EA credit 1, the project team decided it would be best practices to comply with the Advance Buildings Core Performance Guide. The team began investigating the Core Performance Guide during schematic design and we are currently just beginning construction documents. All prescriptive requirements from the Performance Guide for the building\'s envelope, lighting system, mechanical systems, domestic hot water, and construction practices either have been met already or will be met prior to completion. The project understands the nature of a prescriptive guide but is asking for a variance based on the following. All SHGC are below the maximum allowable for this climate zone (.3) but we are considering a much clearer glazing on the north-fa" "The project team is inquiring as to whether or not they can deviate from one of the prescriptive requirements of the Advanced Buildings Core Performance Guide. Prescriptive Compliance path was included in EAc1 for projects that seek a quick and easy approach to credit compliance without using the whole building energy simulation. This approach may appear to be restrictive to the project team, but all of its requirements must be met exactly as specified. Therefore, it is not acceptable to deviate from a prescriptive measure. Please use Option 1-Whole Building Energy Simulation if the project team seeks more flexibility and/or trade-offs. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2095" "2008-04-25" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is a high-rise residential building that is being applied under LEED-CS certification. Living units are being designed without air-conditioning system, since generally the people use natural ventilation during summer. Building spaces with regular occupation, such as bedrooms and living rooms, will be furnished with operable windows only, without mechanical systems. Therefore, under ASHRAE Standard 90.1 the entire building would be defined as unconditioned space, and the envelope does not need to comply with mandatory provisions of that Standard. Following this interpretation, the scope of work for this project would be limited to sections 7, 8, 9 and 10 of ASHRAE Standard 90.1, as the building will be provided with: service water heating; power distribution systems; lighting systems for common areas; and electric motors (stairs ventilators, water pumps and sewage pumps). In order to achieve the minimum energy performance prerequisite needed for LEED certification, only the lighting system for common areas and the service water heating were identified by the design team as the scope of work to be treated under ASHRAE Standard 90.1 and modeling rules of appendix G. This CIR is to clarify three questions: 1. Is this building eligible to certification under LEED, even without HVAC system? 2. If affirmative, the minimum energy performance has to be achieved only for those systems that will be provided by the owner, i. e., lighting system for common areas and service water heating? 3. Can natural ventilation be used as an energy efficiency strategy to achieve the minimum energy performance, in similar way as discussed in a CIR posted in 03/22/2007 (through an Exceptional Calculation Methodology)?" "1) Yes, the project is eligible for LEED certification. 2) Yes, the minimum energy performance and energy savings only applies to systems supplied by the owner. PLEASE NOTE that this project must comply with the mandatory provisions (Sections 5.4, 6.4 (when applicable), 7.4, 8.4, 9.4, and 10.4) of ASHRAE 90.1-2004, which includes the Building Envelope. Section 5.1.2.2 of ASHRAE 90.1-2004 clearly states that ""spaces shall be assumed to be conditioned space and shall comply with the requirements for conditioned space at the time of construction, regardless of whether mechanical or electrical equipment is included in the building permit application or installed at that time."" 3) Yes, natural ventilation can be used as an energy efficiency strategy to achieve minimum energy performance through the Exceptional Calculations Methodology approach outlined in CIR Ruling 3/22/2007. Credit achievement is contingent on the submittal documentation and compliance with the stated method to the satisfaction of the certification reviewer. Please be sure to submit the documentation outlined in the CIR in order to determine compliance during LEED certification. Applicable Internationally. " "1734, 5152" "None" "X" "LEED Interpretation" "2112" "2008-05-27" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "This Project involves the construction of a Testing Facility for High Volume Low Velocity circulation fans. The building consists of a 1940 S.F. General Office Area, a 1940 S.F. Shop Area, and a 40550 S.F. Testing Area with a 50\' joist height. The Testing Area will have in it at most (4) four High Volume Low Velocity circulation fans operating at the same time. The building will have no transient occupants, and a maximum of (6) six employees that will occupy the entire building during normal business hours. This CIR is in reference to the Testing Area. 1. Testing Area: As part of the USGBC New Construction & Major Renovation Version 2.2, the building is required to meet ASHRAE 90.1 2004 (Energy Standard for Buildings Except Low-Rise Residential Buildings), and ASHRAE 62.1 2004 (Ventilation for Acceptable Indoor Air Quality). In accordance with ASHRAE 90.1 2004 the Testing Area is given a baseline LPD (Lighting Power Density) of 1.4 W/SF as is standard for a Laboratory. The only reference in ASHRAE 62.1 2004 (Ventilation for Acceptable Indoor Air Quality) with regard to a Laboratory is listed in Table 6-1 under ""Educational Facilities"" - ""Science Laboratories"". The classification that most closely matches the actual use of the space in the Testing Area for ventilation purposes is a Warehouse, since the population density is low (6760 SF/Person), and the area will never contain ""Laboratory"" chemicals, ""Laboratory"" exhaust hoods, Make-Up air or a population density on par with an Educational Facility Science Laboratory. The Ventilation and Exhaust requirements for a Science Lab are (3) three times that of a Warehouse, and subsequently (3) three times the energy cost. Since the ""actual"" usage of the Testing Area fits the lighting energy requirements of a Laboratory (ASHRAE 90.1 2004) and the ventilation requirements of a Warehouse (ASHRAE 62.1 2004), can the design team consider this space as such for calculations, or does the requirement to stay consistent with room classifications supersede actual building function?" "The applicant is requesting to use the lighting power calculations for one space type and ventilation calculations for a different space type. The ventilation quantities for the Testing facility appear to be associated with process issues associated only with the tests being run, not ventilation requirements associated with Standard 62.1-2004 requirements for indoor air quality. The project team should model the ventilation the same in the Baseline and Proposed Case, and should model the lighting power density requirements based on the closest space type from the ASHRAE Space-by-Space method. " "None" "None" "LEED Interpretation" "2124" "2008-05-27" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is a restaurant, where the main Energy Conservation Measure (ECM) is the implementation of an air conditioning system in the kitchen with focus on the thermal comfort in the occupied areas. The building as a whole is divided in two different occupied zones: dining room and kitchen - food preparation. The dining room is fully air conditioned by a rooftop system. Another rooftop was designed to the kitchen. The kitchen space has two distinct thermal zones: the occupied zone, where people work; and the equipments zone, where the equipments are installed. In order to minimize the influence of high internal heat loads from equipments and considering that only the occupied zone must be maintained within acceptable thermal conditions, the mechanical engineer has defined a strategy where the air distribution system guarantees this condition. Diffusers were installed in order to supply the cooled air mainly in the occupied zone. The equipments zone has an exhaust system only. The heat exchange between occupied and equipments zone was considered in the HVAC design, but the focus of the project was the thermal conditions in the workstation only. For the baseline simulation we are considering the total heat gain of the kitchen (people and equipments). Thus, the conventional system modeled in the baseline provides air conditioning for the entire kitchen. For the proposed design model we are considering the air distribution system analogous to an UFAD system, where only the heat gain of the occupied zone is accounted in the total cooling load. Therefore, in the proposed design model, only the occupied zone is conditioned (cooled), though considering a fraction of the heat gain from equipments zone. The heat and mass transfer between occupied and equipments zone were considered to represent the air distribution system in the proposed design. Computer simulation has shown that the strategy applied in this project provides energy cost savings about 10% when compared to a conventional air distribution system in the baseline. To achieve the prerequisite of energy performance, other 4 p.p. of energy cost savings will be achieved with additional strategies, such as an energy efficient lighting system and a solar heating system for hot water supply. This CIR is to confirm that the modeling assumption described above is acceptable to achieve points under EAc1, considering the modeling of a task air distribution system for the proposed design and a conventional system for the baseline." "The applicant is requesting confirmation on the modeling methodology under EA Credit 1 for a restaurant kitchen area. The project team\'s proposed design will exhaust heat gain from kitchen equipment so that it does not add to the space cooling load. This design is considered standard practice, and as a result, no additional energy savings credit can be claimed. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2128" "2008-05-27" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "This project is located on a multi-building medical campus in Illinois. Typical of a campus, it is composed of numerous existing buildings, parking structures, surface lots and circulation streets. The campus is proposing to build, as separately bid projects, a new inpatient building, some additions to existing buildings, and a new parking structure. Our intent is to pursue LEED Certification for the new inpatient building, a new multi-level parking structure and new portions of site work on the campus, but not the additions to existing buildings. One of the buildings included in the project boundary is an open parking structure. The parking structure includes an enclosed combination stair/elevator lobby. We intend to heat this stair/elevator lobby as well as ventilate the space. A telecommunication closet along with an electrical room will be heated and conditioned as well. The parking garage is not required to be ventilated since it is classified as an open parking structure. The parking garage and stair/elevator lobby will have lighting as required. LEED for Multiple Buildings allows a weighted aggregate for the group of buildings based on their conditioned square footage or aggregate PRM calculation. We would like to confirm only the areas being heated and conditioned are required to be included in the square footage calculation for this particular structure when being considered into the overall aggregate or overall PRM. The lighting square footage will take into account the overall square footage being covered by lighting. Please confirm that we are using the correct calculation methodology for this point." "The applicant has requested confirmation that the weighted average building method from the Multiple Buildings Application Guide is based only on the conditioned area of each building. This is a correct assumption. The language from the EA Credit 1 Multiple language guide states that the ""weighted average for the group of buildings (should) be based on their conditioned square footage."" The definitions of space types from ASHRAE 90.1-2004, page 13, should be used to identify whether spaces are defined as ""conditioned"", ""semi-heated"", or ""unconditioned"". The ASHRAE 90.1 Performance Rating Method (Appendix G) should be used to model each building in the project boundary, including the parking structure. Therefore, all interior and exterior parking garage lighting, elevator energy, etc. should be included into the energy model for the parking structure, regardless of whether the spaces are conditioned or unconditioned. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2167" "2008-05-28" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "See below for treatment of District Thermal Energy systems in LEED-NCv2.2, LEED-CSv2.0, LEED-Schools, and LEED-CIv2.0." "USGBC has developed a document that clarifies how district or campus heating or cooling systems are to be treated in all Energy and Atmosphere prerequisites and credits for LEED-NC, LEED-CS, LEED-Schools, and SSc1, Options K & L under LEED-CI. That document is available for download from the LEED Reference Documents page, here: https://www.usgbc.org/ShowFile.aspx?DocumentID=4176. All LEED-NC, LEED-CS, LEED-Schools, and LEED-CI projects involving district or campus heating or cooling systems that registered for LEED after this posting date must follow that guidance, and such projects that registered before this date may optionally follow that guidance." "None" "None" "LEED Interpretation" "2177" "2008-05-28" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1: Optimize Energy Performance" "See below for treatment of District Thermal Energy systems in LEED-NCv2.2, LEED-CSv2.0, and LEED-CIv2.0." "USGBC has developed a document that clarifies how district or campus heating or cooling systems are to be treated in all Energy and Atmosphere prerequisites and credits for LEED-NC, LEED-CS, and SSc1, Options K & L under LEED-CI. That document is available for download from the LEED Reference Documents page, here: https://www.usgbc.org/ShowFile.aspx?DocumentID=4176. All LEED-NC, LEED-CS, and LEED-CI projects involving district or campus heating or cooling systems that registered for LEED after this posting date must follow that guidance, and such projects that registered before this date may optionally follow that guidance." "None" "None" "LEED Interpretation" "2189" "2008-08-26" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "We are designing an addition to a solid waste transfer station facility for the South Bayside Waste Management Authority in San Carlos, CA. The floor area of the addition will be about 22,000 SF, and the overall building area including the addition will be about 75,000 SF. After the addition has been completed, there will be no wall or physical barrier between the addition and the original structure of the building, although both the new and the existing component will be served by independent HVAC systems, lighting controls, etc. Several floor openings to a tunnel below will prevent traffic between the addition and the existing portion of the building, but the two structures will basically be open to each other. May we certify only the addition to the transfer station, or must the existing building be certified as well? If the addition may be certified as a single structure, we propose that the interface between the addition and the existing building be modeled as a partition with no R-value. Is this acceptable?" "The project team is seeking guidance on LEED certification for an addition to an existing solid waste transfer facility. The project team is also asking for modeling guidance for representing relationship of the addition to the existing facility. The addition may be certified separately and modeled where the performance excludes the existing building if it meets the conditions laid out in ASHRAE 90.1-2004 Table G3.1 Section 2: Additions and Alterations. Given the information presented, the project seems to meet these requirements; however, compliance cannot be assessed outside of the certification process. In modeling the addition and excluding the existing building, the open interface between the addition and the existing structure should be modeled as an adiabatic wall. If the existing building may not be excluded per ASHRAE 90.1-2004 Table G3.1 Section 2; modeling the partition between the existing and new components with no R-value (i.e., as an air wall) is acceptable" "None" "None" "LEED Interpretation" "2198" "2008-06-04" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "See below for treatment of District Thermal Energy systems in LEED-NCv2.2, LEED-CSv2.0, LEED-Schools, and LEED-CIv2.0." "USGBC has developed a document that clarifies how district or campus heating or cooling systems are to be treated in all Energy and Atmosphere prerequisites and credits for LEED-NC, LEED-CS, LEED-Schools, and SSc1, Options K & L under LEED-CI. That document is available for download from the LEED Reference Documents page, here: https://www.usgbc.org/ShowFile.aspx?DocumentID=4176. All LEED-NC, LEED-CS, LEED-Schools, and LEED-CI projects involving district or campus heating or cooling systems that registered for LEED after this posting date must follow that guidance, and such projects that registered before this date may optionally follow that guidance." "None" "None" "LEED Interpretation" "2247" "2008-08-26" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is a major renovation of primarily the common areas in a 37-year old, one and two story, multi-tenant retail mall. The mall was originally designed, permitted and built as an open air mall where the tenants were grouped into multiple buildings with common areas open to the sky between them. During the 1980s, these common areas were enclosed using separate structural and mechanical systems. The total building area inside the LEED boundary is 500,575 sf. The common areas encompass 145, 282 sf. The tenant areas are aggregated in sectors from 20,000 sf to 50,000 sf and separated by one and two hour fire rated exit corridors (the common area of the mall). Both the common and tenant areas of the mall are independently conditioned with multiple small, air-cooled, roof-top systems ranging from 1 to 20 years of age. One of the main goals of the project is to decrease the building\'s energy and carbon footprint by incorporating an extensive HVAC upgrade package to the common areas and requiring all new leases to incorporate sustainable guidelines including HVAC equipment that exceeds ASHRAE 90.1. Question: Will it satisfy the requirements of CS EA Prerequisite 2 and EA Credit 1 to classify the tenant spaces and common areas of an existing multi-tenant retail mall as separate adjacent buildings similar to the requirements found in the LEED for Multiple Buildings under NC v2.2 for the purposes of determining the baseline HVAC system type(s) as defined in ASHRAE 90.1 Table G3.1A? Proposed Interpretation: The design team proposes to classify each tenant sector and the common area as separate campus buildings at the location of the fire rated partitions for the purposes of establishing the baseline HVAC system type. This would allow the baseline HVAC system types for the tenant areas (75,000 sf &" "The applicant is requesting clarification regarding the term ""building"" as it applies to energy efficiency modeling for a multi-tenant retail mall that was previously converted from an outdoor mall to an indoor mall with indoor common areas. From the description provided above, it appears that the retail mall should be classified as a single building: the common areas are directly connected to all of the retail spaces and/or the retail spaces are connected to one another; significant transfer of air is likely between the retail spaces and the common area spaces; and the use of the building (as a retail mall) is consistent throughout the whole project. There was no strong justification provided by the applicant to justify why the retail spaces should be considered as separate buildings. Therefore, the project should be considered a single building. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2249" "2008-08-26" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "This project is a commercial office building located in New York City on a uniquely shaped parcel of land. The building is located on an asymmetrical triangular shaped lot of 5,549 sq. ft. While the building is six stories tall, the total square footage of the building is only 34,300 sq. ft. This type of building is quite unique to dense urban areas in making the most of a small lot. Due to the fact that this building is unique in terms of its height in comparison as compared to its sq footage, this CIR is asking if an allowance can be made to use a more comparable baseline per ASHRAE 90.1-2004 in the energy model. The following are the baseline building types outlined in ASHRAE 90.1-2004 for selection of Baseline HVAC System Types: - Residential - Nonresidential & 3 floors or Less & < 75,000 sq. f.t or 5 Floors or Less & 75,000 sq. ft. to 150,000 sq. ft. - Nonresidential & More than 5 Floors or >150,000 sq. ft. Per these requirements this small 34,300 sq. ft. building would be using the same baseline system descriptions as significantly larger facilities. We are proposing that because of this discrepancy that the third option of Nonresidential & 4 or 5 Floors & < 75,000 sq. f.t or 5 Floors or Less & 75,000 sq. ft. to 150,000 sq. ft. be a viable baseline for the project to use in the energy model. The systems that differ between the two baselines are as follows: Nonresidential & 4 or 5 Floors & < 75,000 sq. ft. - System 5 Packaged VAV w/ Reheat OR System 6 - Packaged VAV w/ PFP Boxes Nonresidential & More than 5 Floors or >150,000 sq. ft. - System 7 VAV w/ Reheat OR System 8 - VAV w/ PFP Boxes." "The applicant requests an exception to ASHRAE 90.1-2004 Appendix G modeling methodology that would allow the project to model a Baseline HVAC system type that more closely reflects the system type used for similarly-sized buildings. While the project\'s efficient use of land is commendable, the CIR process cannot be used to grant exceptions from ASHRAE modeling requirements. The project team must model the building using the applicable system type determined from the system mapping in Table G3.1.1A. Since the project is less than 100,000 square feet, the project team may opt to document credit compliance using the Option 3 prescriptive compliance path (the Advanced Buildings Core Performance Guide) rather than the Option 1 Whole Building Simulation compliance path. However, if the whole building simulation compliance path is selected, the project must follow all applicable ASHRAE Appendix G modeling protocol. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2258" "2008-10-03" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Background The Phoenix Sky Harbor International Airport Automated Train project consists of an automated electric train which travels on an open, elevated railway serving three train stations. One station is attached to the existing air terminal building #4, one makes connection to the municipal light rail station adjacent to the airport at 44th Street, and the third (the EEL Station) is located on the rail system part way between these stations and adjacent to an existing parking garage. The terminal #4 and 44th St. stations are enclosed and conditioned and the application of LEED criteria is fairly straightforward. It has been suggested by value engineering that the EEL station be constructed as an ""open"" or unenclosed, unconditioned structure with a roof and interior lighting, but no exterior walls. The station will include normally unoccupied, enclosed, and conditioned ancillary equipment rooms which house electrical and communications/security equipment. It is anticipated that these ancillary areas will constitute about 5% of the total building area. Credit Interpretation Request This question deals with how the unconditioned, unenclosed portions of this building can evidence compliance with EA prerequisites and credits. In researching past CIRs on the USGBC website several cases involving unconditioned buildings were found, but none matched our project sufficiently to provide a level of confidence in the interpretation of requirements. In the proposed design, the unconditioned, unenclosed portions of the building will be naturally ventilated with no HVAC equipment, while the enclosed ancillary equipment spaces will be conditioned with conventional A/C or evaporative cooling and electric heating equipment. It is desired that the entire building be considered for certification, not just the ancillary areas. In configuration, this building most resembles a parking garage where there is lighting, vertical transportation, and conditioned ancillary areas, but no conditioning or enclosure of the occupied areas. The LEED NC Version 2.2 Reference Guide (First Edition) indicates on page 181 under HVAC system types that ""For areas of the project without heating or cooling systems (such as parking garages), there is no need to model heating or cooling systems in either the Proposed or Baseline designs. This was supported by the CIR ruling dated 1/29/2008 relating to a CIR submitted on 1/11/2008 that addressed energy use simulation of unconditioned buildings. The Ruling stated ""For EAc1, these buildings would be treated very similarly to unconditioned parking garages, where the envelope does not necessarily need to be modeled, but the electric loads from the lighting and fans are included in the energy calculations."" Will it be permitted to treat the EEL station in this fashion, where the energy simulation will include use by lighting, vertical transportation and other ancillary energy uses, but not HVAC systems in the unenclosed areas? The HVAC systems serving conditioned equipment rooms will be included in the simulation and their performance will be compared with the baseline systems specified by ASHRAE Std 90.1 - 2004, Appendix G. Since the envelope requirements of ASHRAE 90.1 - 2004 do not apply to unenclosed and unconditioned buildings, may we assume that EAp2 is automatically satisfied for the unconditioned portions of the buildings and only the conditioned, ancillary portions of the building must comply?" "The project team is requesting guidance on modeling an unenclosed structure under EAc1 - Whole Building Simulation, and how to satisfy EAp2 for the same building. For the unenclosed portions, the project team may follow the instruction given in the cited CIR (dated 1/29/2008); treating the unenclosed portion similarly to an unenclosed parking garage. The enclosed portions should be modeled as conditioned and adhere to the ASHRAE 90.1-2004 standard Appendix G modeling guidelines. For EAp2, as stated in the referenced CIR, the applicable minimum requirements of ASHRAE 90.1-2004 must be met under EAp2. This holds true for both the unenclosed and enclosed portions of the structure. The project must also include occupied interior space in order to be eligible for certification. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2291" "2008-08-26" "New Construction" "EAc1: Optimize Energy Performance" "We are inquiring regarding which compliance option to use for 3 Lodge/Conference Center buildings. 1 building is 3 stories with approximately 50,000 square feet, 2 buildings are 2 stories with approximately 40,000 square feet. Each building contains meeting/conference space as well as hotel/lodge guest rooms. According to ASHRAE 90.1-2005 Appendix G (pg. G-2): ""The building performance rating method may be used for new buildings as well as alterations and additions to existing buildings. The only exception is for new buildings, alternations or additions that do not have a mechanical system. In this instance, the method may not be used."" According to ASHRAE 90.1-2004 Appendix G (pg. G-22): ""Residential spaces in buildings are used primarily for living and sleeping. They include, but are not limited to, dwelling units, hotel/motel guest rooms, dormitories, nursing homes, patient rooms in hospitals, lodging houses, fraternity/sorority houses, hostels, prisons, and fire stations. The scope of Standard 90.1, in terms of residential spaces, applies just to spaces with four or more stories, so low-rise residential is excluded."" The LEED reference guide states that: ""The provisions of this standard do not apply to single-family structures of three habitable stories or fewer above grade, manufactured houses (mobile or modular homes), buildings that do not use either electricity or fossil fuel, or equipment and portions of building systems that use energy primarily for industrial, manufacturing or commercial processes."" We propose having the option to use a whole building energy simulation to calculate compliance with this credit based on the Appendix G energy performance method due to the fact that these buildings do not clearly fit into any of the categories provided. Considering the nature of the project and that it contains guest rooms and conference space we are requesting a designation of ""Nonresidential, Less than 3 floors or less than 75,000 square feet"" per Table G-A - Baseline Building HVAC System Types and Descriptions as we feel it best fits this project." "The project team is requesting guidance on the most applicable option to pursue under EAc1 for three lodge/conference buildings. Specifically, the team is seeking clarification on whether Option 1 - Whole Building Simulation, and selecting ""Nonresidential & 3 Floors or less. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2300" "2008-08-26" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1: Optimize Energy Performance" "We have multiple new projects on the University of Colorado at Boulder\'s campus all seeking LEED certification which will be serviced by a new heating and cooling plant, also seeking LEED certification. The schedule of the projects is such that the earliest building complete will be complete and occupied approximately one year prior to the completion and start up of the new heating and cooling plant. Although this project is completely designed to be serviced by the new plant (and the drawings will reflect this), the project schedules will create a lapse where the building will have to be serviced by a temporary means until the new heating and cooling plant is operational. The current plan is to utilize temporary chillers and boilers. We believe it is appropriate for our energy model and all other LEED submittals to reflect the final connection to the CUP and not the temporary equipment. Please confirm this approach is acceptable. In addition, please clarify whether the temporary equipment must be commissioned to satisfy EAp1. The new CUP will be commissioned as well as all ""downstream"" equipment at each building in accordance with the May 28, 2008 CUP memo." "The project team is requesting permission to use the designed central plant specifications for EAc1 Option 1 and all LEED submittals versus the temporary plant that will be connected to the newest building on campus seeking LEED certification. The project team has also requested exception from the EAp1 requirement for commissioning the temporary equipment. The permanent equipment intended for the campus central plant may be used in submitting for EAc1 if the project team provides a letter on owner letterhead stating that the permanent central plant is fully funded. Please also include in the letter a comparison of the schedule of completion for the building in question to a schedule of completion for the central plant. Additionally, if the intent is to use this for other prerequisites and/or credits, this letter should address adequately how the requirements for all credits and prerequisites are being met effectively. However, the temporary equipment shall not be exempt from meeting the requirements of EAp2 - Minimum Energy Performance or EAp1 - Fundamental Commissioning, as this temporary equipment will be in operation for at least one year, if not more. It is necessary that the project team meet those requirements, i.e., a basic minimum level of energy performance and fundamental building systems commissioning for even the temporary equipment." "None" "None" "LEED Interpretation" "2306" "2008-10-03" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1: Optimize Energy Performance" "The purpose of this CIR is to obtain written confirmation and clarification that the use of TAS 9.0.7 software (by EDSL) can be approved as a energy modeling tool for pursuing EA Credit 1 and EA Pre-requisite 2 After reviewing ASHRAE 90.1-2004 Appendix G section G2, where all requirements are specified, we would confirm that the TAS 9.0.7 computer simulation software tool has the following capabilities: a. 8760 hours per year: TAS is able to simulate on an hourly basis over a total of 8760 year. b. Hourly variations in occupancy, lighting power, miscellaneous equipment power, thermostat set points, and HVAC system operation, deigned separately for each day of the week and holidays: TAS has the capability of adding schedules for all of the above. Different load profile can be created for different times of the day and for different days in the week. The possibility of creating out of hours conditions, nigh time setback temperature, etc. is also available. c. Thermal mass effect: TAS accounts for thermal inertia in the space. d. Ten or more thermal zones: TAS can handle more than ten different thermal zones e. Part-load performance curves for mechanical equipment: TAS is able to simulate part load performance for fans and pumps. TAS can model both constant and variable speed pump systems for primary and secondary. In the air side, different systems can be simulated (i.e. VAV, fancoils, etc) with variation in fan consumption as the load varies. f. Capacity and efficiency correction curves for mechanical heating and cooling equipment: TAS has the capability to incorporate correction curves, even combination of numbers of different types of boilers and chillers within the same project. g. Air-side economizers with integrated control: TAS can incorporate free cooling chillers. It has also the capability to model heat recovery air handling units with by-pass control with an air temperature set point. h. Baseline building design characteristics specified in ASHRAE 90.1-2004 Appendix G section G3: TAS allows the user to build a model for the baseline building using the characteristics specified in G3 and also those in G2.1 (same weather data and same energy rates), although the program does not generate it automatically and it is the user that has to carry out the modeling. 2.0 CIR - Design Energy Builder Energy Plus Modeling Tool Approval Please could you confirm whether the USGBC have approved the use of Design Energy Builder latest Version 2.2 of Energy Plus Software modeling Tool and if this is not the case is the software tool currently accepted by the USGBC." "The applicant is requesting approval to use EDSL TAS 9.0.7 software to document compliance with the energy simulation requirements in EAp2 and EAc1. USGBC does not maintain a list of approved energy modeling software. Instead, the project team must ensure that the simulation tool satisfies the requirements of ASHRAE 90.1-2004 Appendix G Section G2. The Design Builder energy simulation and visualization tool incorporates the EnergyPlus simulation engine. EnergyPlus should meet the ASHRAE 90.1 Appendix G Section G.2.2 requirements. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2339" "2008-10-24" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "Our project is a 65,000 SF injection molding manufacturing facility and office near Detroit, MI. The project consists of 10,000 SF of air-conditioned office space, and 55,000 SF of air-conditioned manufacturing space, which includes injection molding equipment, as well as occupied assembly areas. The energy required for the manufacturing process exceeds 85% of the facility\'s total energy load. To achieve the 14% minimum energy savings, process load energy savings must be taken into account. As a result of the high energy loads associated with the manufacturing process, as well as the energy not falling under ASHRAE 90.1-2004, an exceptional calculation method must be established for the manufacturing area. Both the office area and the manufacturing area are conditioned. Space cooling in these areas will be achieved through constant volume rooftop units, and will be modeled through a standard energy modeling software like Trane Trace 700. The manufacturing process includes injection molding machinery which is cooled through a chiller & cooling tower assembly. The load on the chiller and cooling tower will not fluctuate (except for operational and non-operational hours, which will be achieved through a schedule). The chiller and cooling tower performance will be run in a separate energy model using this constant load to determine the overall energy used based on the outdoor air conditions throughout the year. The Chiller and cooling tower energy used will then be input into the original model as annual process energy. The Chiller and Cooling Tower efficiencies for the baseline will be based off ASHRAE 90.1-2004 minimum standards. The injection molding equipment proposed is state-of-the-art and very energy efficient compared to the standard injection molding machinery that is the industry standard. Using the client-provided operational times for the equipment we will be able to estimate the total energy used by this injection molding equipment, as well as the total energy that would be used by industry standard equipment. This will be used to determine the annual energy for both the baseline and the proposed design. We will then input these amounts into the original energy model as annual process energy. For comparison purposes, we also have a similar plant by the same client that uses the industry standard machines. By comparing the amount of equipment and square footage of this plant, we can achieve a very accurate idea of how much energy the new plant is saving. All calculations showing how the machinery energy was determined, and results of planned field monitoring, will be explained in an excel spreadsheet. Equipment descriptions and energy loads will be shown for all machines that will be used, as well as for comparable industry standard machines. Once the process equipment, both baseline and proposed, have been input into the overall energy model as process loads, the standard reports issued from the model will be used for the LEED Reports. In addition, we will provide the sub-energy models of the process equipment that is weather-based. Please confirm that our assumptions and method of calculating the process energy load for both the base and proposed design cases are acceptable for EAc1." "The applicant is requesting acceptance of the proposed energy modeling methodology for a process dominated project. While the overall process for exceptional calculations seems reasonable, the applicant must make the following changes to the calculation methodology: 1. Include all loads in the same model and not in two separate models. This will allow the models to accurately reflect any interactions between the process loads and the space conditioning loads. 2. Provide a side-by-side comparison of the industry standard equipment, its age with the new proposed equipment and define an energy efficiency metric for each piece of equipment (e.g. kWh/ pound of material processed). Also provide list of modifications that make the new equipment more efficient. 3. Provide detailed utility bills from the comparison facility for reference. 4. Provide the operation schedules for the facility and the equipment. Please note that while this Credit Interpretation Ruling provides guidance on the exceptional calculation methodology, the actual savings and credit available for the strategies will be determined only during the review of the actual documentation. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2348" "2008-10-24" "New Construction" "EAc1: Optimize Energy Performance" "The reference project is a manufacturing plant with warehouse space and office space. The manufacturing equipment process loads are very high, on a scale which is more than 10:1 higher than the base building loads. The base building includes numerous energy and environmental attributes that would make LEED certification feasible, but, as stated, the manufacturing equipment process loads eclipse base building loads. Even using the baseline HVAC selection exemption stated in Appendix G (G3.1.1) proves inconsequential to energy savings. As a result, the minimum 2 point prerequisite under this credit are unavailable when this manufacturing equipment load is included. Can the USGBC please advise the project team on how this issue can be addressed in order to achieve LEED certification? For instance, defaulting to 25% process load for the facility would allow the 2 prerequisite points to be easily achieved based on the baseline building high performance features." "The project team is seeking guidance on meeting the two-point minimum for EAc1 for a process-energy-use-dominated facility. It is not clear from the request, whether the project team has explored possibilities of reducing process energy use and documenting the same, which might make it possible to achieve the two-point-minimum required under this credit. Per LEED NC v 2.2 Reference Guide, EA Credit 1, under the Calculations section, sub-section Process Energy: ""However, project teams may follow the Exceptional Calculation Method (ASHRAE Std. 90.1 G2.5) to document measures that reduce process loads. If credit is taken for process loads, the calculation must include reasonable assumptions for the baseline and proposed case"". As there is still a possibility of achieving the two-point-minimum under this credit, a variance from the established methodology cannot be approved. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2349" "2008-10-24" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is a 400,000 SF office building. The building structure and core spaces (stairwells, elevators, etc.) will remain. A new building envelope (skin) on the south and east elevations will be provided. Existing exterior walls will remain on the north and west elevation, with new insulation and windows. The majority of existing building systems will be replaced, with the following exceptions: - There are two existing chillers, one will be replaced and one will remain - Existing mechanical, storm, sanitary, and fire protection pipe risers will remain - The existing garage ventilation system will remain Since we are reusing the building structure, which limits some of our energy reduction strategies (building orientation, daylighting, etc.), and also salvaging existing exterior walls, mechanical equipment, and piping, we feel that we should qualify as an Existing Building Renovation. Please clarify if this assumption is correct." "The project team is requesting guidance to classify the project as an Existing Building Renovation. Due to the large portion of the building and systems excluded, this is acceptable. However, care must be taken to follow the requirements of ASHRAE 90.1-2004 Appendix G, as specific requirements for modeling existing building portions must not be ignored. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2360" "2008-10-24" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1: Optimize Energy Performance" "Our project includes a 120,000SF addition/renovation to a 140,000SF office building. Lighting control systems were installed to provide increasing levels of energy performance savings by adjusting the initial foot-candle levels down to IESNA acceptable maintained foot-candle levels. The project includes expansion of the existing Eaton\'s POW-R-Command lighting control system. Our approach is not proprietary to the Eaton system and could be applied to any automatic lighting control system. Use of our lighting control approach results in energy savings beyond the default 10% energy savings limit identified in Table G2.3 within ASHRAE 90.1-2004, Appendix G. We are requesting the USGBC allow us to use the alternative method to modify the lighting schedules beyond the 10% limit in accordance with the standard as outlined below. Standard lighting foot-candle design is based on maintained foot-candle levels understanding that initial levels will be higher and will degrade over time. For this project, the light loss factor is 85% of initial fixture performance. This standard design approach typically results in initial lighting designs that are over-lit and a higher w/sf value. For this project, the lighting foot-candle design and layout provides roughly 20%+ more initial illuminance than IESNA Recommended Guidelines, however upon installation, the lighting levels are dimmed through the lighting control system to those foot-candle levels which meet the IESNA Guidelines for maintained lighting illuminance. Over time, as lamp depreciation occurs, the illumination performance is automatically increased to consistently maintain the IESNA Guidelines level. This control approach has been in use within the existing facility for the past ten years. Dimming control of the system is programmed and performed by facilities staff only and the individual occupants do not have control capabilities. This feature can not be overridden by the occupants. Controlling and operating the lamps in this manner in the existing building have resulted in a 33% reduction in electrical energy use plus additional cooling capacity savings when compared to an un-controlled lighting approach and have resulted in approximately 40% lighting energy savings within the new addition. ASHRAE 90.1 - 2004 Appendix G, Paragraph G.25 - Exceptional Calculation Methods, states ""When no simulation program is available that adequately models a design, material, or device, the rating authority may approve an exceptional calculation method to demonstrate above-standard performance using this method"". However, in Table G3.1, paragraph 6(g), the standards states ""For automatic lighting controls in addition to those required for minimum code compliance under 9.2, credit may be taken for automatically controlled systems by reducing the connected lighting by the applicable percentages listed in Table G2.3. Alternatively, credit may be taken for these devices by modifying the lighting schedules used for the proposed design, provided that credible technical documentation for the modifications are provided to the rating authority. We believe our project approach meets the intent of the alternative modified schedule approach. The system, as installed:  Exceeds the energy savings allowed using standard building modeling protocol  Meets the intent of the credit  Provides a creative method to produce additional measurable energy performance savings  Reduces environmental impact" "The project team is requesting an allowance to account for energy savings from lighting control above the 10% as defined in ASHRAE 90.1-2004. As stated in ASHRAE 90.1-2004 Table G3.1, No. 4 Baseline Building Performance, non-standard efficiency measures such as lighting controls can be modeled by modifying schedules. The schedule change and energy savings should be modeled and submitted as an exceptional calculation method (Section G2.5 of ASHRAE 90.1-2004, Appendix G), with documentation that supports the proposed lighting schedule. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2395" "2009-01-07" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our project is a 75,348 sf existing 2-story office building to be renovated and constructed to achieve LEED NC2.2 certification. Tenant #1 will occupy more than 50% in the initial buildout, thereby establishing the project as a Major Renovation under LEED NC. The balance of the building will eventually be occupied by a second tenant, not yet identified. The HVAC system will be installed for Tenant #1, but not for Tenant #2. It is our intention to perform the Energy Model as though the entire building will be air conditioned although the actual equipment will not be installed for Tenant #2 initially. Documentation will be provided including lease agreements verifying that 100% of the leased square footage complies with LEED requirements and a statement signed by the Owner verifying that all lease agreements will comply with the Tenant Guidelines. The Tenant Guidelines will establish the lighting power density, minimum HVAC efficiencies, etc. Additionally a letter from the Owner outlining requirements exceeding ASHRAE 90.1-2004 will be provided to future tenants and will be strictly enforced. We seek confirmation that the approach we propose will be acceptable for LEED NC2.2 certification of the building without the remaining Tenant Space #2 being occupied, provided sufficient LEED credits are earned." "The applicant is requesting approval to model tenant fit-out portions of the building with identical HVAC systems, lighting power densities (LPDs), etc. to the occupied portion of the proposed building. No HVAC, lighting, etc. system will be provided for the tenant fit-out portions of the building prior to LEED certification. Therefore, energy simulation parameters for these spaces are not known and need to be documented very specifically in the \'tenant lease agreement\' and not just be general. Specifics should include all of the following - system type, equipment efficiency, controls, system capacity and square foot load assumptions. The tenant fit-out portions of the proposed building should be modeled using baseline parameters and methods specified in ASHRAE 90.1-2004 Appendix G. Please note, however, that the parameters of any installed components (e.g., building envelope, shading, etc.) that are within the scope of the building construction may be modeled using the parameters shown on design drawings. In order to document this approach, the project team should provide a narrative which clearly identifies what portion of the building will not be occupied by the owner and what parameters in the tenant fit-out portion will be modeled according to the design drawings. The LEED submittal template should include both the proposed case parameters and systems that correspond to the owner occupied space and the tenant fit-out space." "None" "None" "LEED Interpretation" "2397" "2009-01-07" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project is a metal recycling facility primarily used for shredding and separating metal to be recycled. The building is a very process intensive facility containing many large motors - the largest of which is 4,000 HP. ASHRAE Standard 90.1, Appendix G - Table G3.1, section 12 states that for the baseline: ""Other systems, such as motors covered by Section 10, and miscellaneous loads shall be modeled as identical to those in the proposed design. Where there are specific efficiency requirements in Section 10, these systems or components shall be modeled as having the lowest efficiency allowed by those requirements."" Because such a large portion of the facilities energy consumption will result from the large motors (greater than the 200 HP upper limit of Section 10) it will be difficult to obtain any appreciable improvement over the baseline performance if the baseline large motors (> 200 HP) are to be modeled with the same efficiencies as the proposed design. For these motors that exceed the 200 HP, would it be acceptable to use the minimum efficiencies for 200 HP motors as outlined in Section 10 for the baseline building performance? Or is there another way that we can take credit for using high efficiency motors? Additionally, the project is planning on incorporating many other sustainable features into the project that will allow for us to achieve a Silver, and possibly a Gold rating. However, if 2 points must be achieved from EA credit 1 in order to be certified, then it does not look like we can become certified despite all of the other LEED points we could achieve. Do we need to receive a minimum of 2 points under this credit to be eligible to certify the project under LEED NC version 2.2?" "The applicant is seeking guidance regarding how to meet the two-point minimum required for EAc1 for a process-load dominated building. Per CIRs dated 3/23/2007 and 10/24/2008, process loads for the entire facility must be included in the energy simulation. Per the CIR dated 3/23/2007, the baseline HVAC system may be modified according to Exception to G3.1.1(b) in ASHRAE 90.1-2004. Per a CIR dated 10/24/2008, the project team may want to consider attempting to document energy savings for process energy use. The project should use the Exceptional Calculation Methodology (ECM) outlined in ASHRAE 90.1-2004 Section G2.5 to document process energy savings. If attempting to demonstrate process energy savings, the ECM must include calculations and reasonable assumptions for motor efficiency in baseline and proposed cases. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2416" "2009-02-03" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "Our project is a newly constructed, 825,751 square foot automotive manufacturing facility in the midwest. The ventilation requirements for our facility, as set forth by ASHRAE 62.1, Section 2.2 states: ""Additional requirements for laboratory, industrial, and other spaces may be dictated by workplace and other standards,."". Industrial facilities in this location fall under the requirements of the Michigan Occupational Safety and Health Administration (MIOSHA). Per MIOSHA\'s, health standards (""Part 520. Ventilation Control""), R325.52007 Exhaust ventilation systems, Rule 7 states : ""The minimum rate of exhaust ventilation for places of manufacturing, processing, assembling, maintenance and repair, or storage of material shall be 1 cubic foot of air per minute per square foot of floor area. This amount of exhaust ventilation may be provided by local exhaust, general exhaust, or both. The director may permit a variance if contaminant control is accomplished at a lesser rate of ventilation."" MIOSHA has stated that an allowable level of contaminant control for dust/mist particulate would be 5 mg/cubic meter. In an attempt to save ongoing heating, cooling and ventilation expenses, the Owner chose to design the new facility in an innovative manner that could attain contaminant control at a much lesser ventilation rate than the default 1 CFM/SF that is set forth by MIOSHA and used by other automotive manufacturing facilities. The manufacturing facility has set a target of 0.5 mg/cubic meter, significantly lower than the MIOSHA required level of contaminant control. In order to reach this high level of contaminant control, they implemented the following innovative approaches: 1 - For the machining and grinding processes, enclosures were constructed and oil mist/dust collection systems were implemented with HEPA filtration. 2 - For the parts washers, enclosures were constructed and local exhaust ventilation systems were designed to capture contaminants at the source. 3 - For processes using hazardous materials, local exhaust ventilation systems were designed to capture contaminants at the source. 4 - ""Dry floor guarding"" systems have been implemented in the machine tool enclosures in order to minimize any escaping mist from the process. 5 - Micro-bacteria resistant coolants are used in the plant and biocides and utilized and monitored in order to control the bacterial counts in such systems. These control measures are over and above what is done in a typical, newly constructed manufacturing plant. With these control measures being utilized, extensive testing was done through the manufacturing facility to ensure that MIOSHA (and the much more stringent company requirements) exposure limits were being met. During the testing, the facility was ventilated at a rate of 0.21 CFM per square foot. At this ventilation rate, the facility was far below the company\'s target exposure limits, never measuring higher than a 0.13 mg/cubic meter exposure level. The Owner operates their facility at a ventilation rate of 0.5 CFM per square foot. This adds another level of safety factor to the building design. We are proposing that we run the energy model, in both the baseline and proposed case, with a ventilation rate of 1.0 CFM per square foot. We then intend to use the Exceptional Calculation Methodology of ASHRAE 90.1 to quantify our energy cost savings by lowering the ventilation rate. We intend to re-run our ""proposed"" model with 0.5 CFM per square foot to determine the cost savings for this exceptional calculation." "The applicant is proposing that energy savings due to ventilation load reduction resulting from several pollutant source control measures be approved as an Exceptional Calculation Methodology (ECM). The use of baseline and proposed case exhaust rates above those required by ASHRAE 62.1-2004 Section 6.2.8 are acceptable per ASHRAE 62.1-2004 Section 2.2 and the requirements specified by Michigan Occupational Health and Safety Administration (MIOSHA). Since it is a non-regulated process load, the project team must establish reasonable assumptions under full operational conditions for the baseline and proposed case. It appears that the project team has put a substantial effort into identifying and controlling sources of indoor pollutants and in an effort to reduce ventilation loads. Additionally, testing has been conducted to verify that the particulate concentrations are well below MIOSHA requirements even at reduced ventilation rates. The proposed documentation of energy savings from ventilation load reductions in the proposed case may be documented as an ECM. Please note that the favorable ruling of this CIR does not guarantee credit acceptance during a review. The project team should provide sufficient documentation to support the proposed ECM. Also note that the ruling is specifically applicable to the project in question due to the substantial efforts made to control sources of indoor air contamination at the source and testing for compliance; the ruling is not necessarily applicable to projects with different circumstances." "10291" "None" "LEED Interpretation" "2423" "2009-02-03" "New Construction" "EAc1: Optimize Energy Performance" "We\'re requesting confirmation for a proposed modeling methodology to simulate humidity control in the baseline system. Our project is a multipurpose facility that includes warehouse, manufacturing, laboratory and office spaces. The manufacturing portion of the building comprises roughly 45% of the overall facility. Numerous energy saving measures have been incorporated into this facility and we believe that our project meets the intent of this credit. However, the manufacturing portion of the facility requires some unique parameters, primarily humidity control, that the ASHRAE 90.1-2004 baseline system, system 3 PSZ-AC, is unable to simulate through normal means. The prominent standards (Issued by the U. S. Food and Drug Administration and the International Society of Pharmaceutical Engineers) that spaces of this nature are designed to are as follows:  21 CFR Part 210 - Current Good Manufacturing Practice in Manufacturing Processing, Packaging or Holding of Drugs; General  21 CFR Part 211 - Current Good Manufacturing Practice for Finished Pharmaceuticals  ISPE Design Guidelines - Volume: 3 Sterile Manufacturing Facilities These standards regulate the practice of how products are to be manufactured and the environment the products are to be controlled within. Four parameters to be controlled of a critical nature are Air Volume, Temperature, Pressure and Humidity. The air volume, temperature, pressure, and humidity need to be controlled to conditions proper to the production of the drug and need to be consistent to insure consistent quality of the drugs. Humidity control is an FDA requirement, but it is a significant contributor to energy consumption for the facility. Requirements for air volume, temperature, and pressure have been consistently applied to both the baseline and proposed energy simulation cases. Humidity control to a level of 45% can only feasibly be met and maintained year round by employing ""reheat"" control wherein the air is cooled, to 50F, to remove moisture and then ""reheated"" to maintain space temperature. It is for this reason reheat is being utilized and the commensurate energy consumption is greater than that used by a ""cooling only"" mode of operation. Uncontrolled humidity can cause degradations in the product that are often responsible for inconsistent quality and are cited by the FDA as such. Humidity control through reheat was approved in the CIR dated 6/19/2007. According to the CIR ruling, ""Humidity control requirements should be the same as in the proposed building, even if it requires reheat to be modeled with that system type."" Because the baseline system (system 3, PSZ-AC) is unable to meet/simulate the humidity control required, we are requesting confirmation for the following methodology to model the humidity control in the baseline simulation. First, the energy required to dehumidify (cool) the air from 58F to 50F must be added to the baseline energy simulation. The baseline model has shown that 58F will satisfy temperature requirements for these manufacturing spaces. Second, the additional energy required to reheat the air from 50F to 58F must be included. Please confirm whether or not the proposed steps are acceptable to model reheat for this facility." "The applicant is requesting the use of an alternative modeling strategy in order to achieve specific temperature, air volume, pressure, and humidity requirements for a climate controlled manufacturing environment. The request is based on the assumption that the baseline system type for the manufacturing spaces is packaged single zone and the belief that the simulation program is unable to meet the space humidity requirements with this system type. If the space is being conditioned to meet the requirements of the manufacturing process and not the requirements of occupants, then the load might be classified as a process load. If this is the case, the approach detailed in a CIR ruled on 5/27/08 should be followed. Specifically, the baseline mechanical system serving a process load is of the same type and has the same controls as the proposed design. The efficiencies of the components of the baseline system are minimally-compliant with ASHRAE 90.1 Chapter 6. The proposed design efficiencies are as-designed. To account for energy savings for mechanical system improvements (or other unregulated components associated with process loads) that go beyond what is typically done for the application, an exceptional calculation method can be followed." "None" "None" "LEED Interpretation" "2441" "2009-01-14" "New Construction, Existing Buildings, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "This project is a remodeling of an existing office building that will include the addition of a Data Center. The Data Center will make extensive use of server virtualization to save energy, space and money. Server virtualization is the technique of replacing multiple servers with one server running multiple ""virtual servers"" on one larger, high performance server. In their existing Data Center, our client runs an average of 8 virtual servers on each high-performance server. Although the high performance server uses more energy than any one of the low to medium performance servers that it replaces, this results in a net energy savings of between 60-75%. Our question is: Under EAc1, Option 1, may we use the Exceptional Calculation Method to model the energy savings accountable to server virtualization?" "The applicant may use the Exceptional Calculation Method to take credit for any energy savings available from the server virtualization technology. Be sure to include as supporting documentation under EAc1 all assumptions made in the calculations, detailed data, any actual measurements taken to support the savings claims and any other pertinent information. Please note that the actual amount of credit will be determined by the review team at the time of the review. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2456" "2009-02-20" "New Construction" "EAc1: Optimize Energy Performance" "We are attempting to clarify the requirements of the energy model for tenant fit-out spaces within a residential building that was registered under the LEED-NCv2.2 rating system on 05/21/2007. The project is a 1,200,000 square foot residential building with 330,000 square feet of commercial space that will be occupied by a single tenant and will be located primarily below grade and on the first floor of the building. The developers will build the facade of the 70,000 square foot ground floor section to the tenant's specifications. The tenant will also specify their own MEP systems. In addition, there will be up to another 40,000 square feet of tenant fit-out spaces comprised of retail and civic functions. The facade of these tenant fit-out spaces will be built to the developers specifications; however, the MEP systems within these spaces will not be under the control of the developers. An Administrative Ruling dated 8/27/2007 requires tenant guidelines be provided to ensure that future tenants are informed of, and can meet LEED prerequisites and requirements for the credits pursued by the project. The ruling further states that the project teams need not require any particular energy efficiency or green measures for tenant fit-out spaces. The team would like to confirm, through the above mentioned ruling, that energy usage of the tenant fit-out spaces can be excluded from the energy model. Alternatively, since the developers do not control the facade or the MEP systems for the 330,000 square foot tenant fit-out space, the developers are considering applying for a LEED rating only for the portions of the building in which the developer specifies the facade (exclude a portion of the building below the 2nd floor in which the tenant is specifying the facade and MEP systems). The other tenant fit-out spaces (retail and civic functions) would be included in the LEED application. Please advise on whether these paths are acceptable." "The project is seeking clarification if the project may exclude portions of the building which they do not control from the building\'s energy model. The LEED-NC rating system is intended for whole building certification, and therefore the project must included in the LEED Application and energy model the entire building without any exclusion. Therefore, both the 330,000 and the 40,000 tenant fit-out space may not be excluded from the energy model. Additionally, these two tenant fit-out spaces may not be excluded from the LEED NC Application. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2461" "2009-02-20" "New Construction" "EAc1: Optimize Energy Performance" "We are trying to determine the correct baseline HVAC system type for a new 9 story, 400,000 ft2 hospital in San Francisco. Per 90.1-2004 section G3.1.1 exception C, the baseline should be System Type 3 (packaged single zone systems with DX cooling) in "".any zones having special pressurization relationships, cross contamination requirements, or code required minimum circulation rates."" This exception is vague but appears to require System 3 in almost all hospital zones since almost all hospital zones have ""special pressurization relationships, cross contamination requirements, or code required minimum circulation rates."" We are not aware of any large, multi-story hospitals in the U.S. that use packaged single zone systems. Such systems are simply not practical or even possible for most zones in a large hospital. For example, it would probably be impossible to find enough roof or shaft space to serve a 9 story hospital with rooftop packaged single zone units. A few exceptional hospitals are using variable air volume (VAV) reheat in some zones with special pressurization requirements but the majority of hospitals being built today use constant volume (CV) reheat in such zones. The 90.1 baseline is intended to represent the industry standard of care and constant volume reheat (not packaged single zone) is the current standard of care where pressurization is required. Constant volume is the industry standard because it is simpler and considerably less expensive and less maintenance than variable volume. Constant volume systems in hospitals either have no terminal units or have standard CV terminal units on the supply side but not on the return/exhaust side. VAV systems, on the other hand, require terminal units on both the supply and return/exhaust sides. Furthermore, terminal units in VAV systems in California are typically not standard VAV terminal units (e.g. butterfly damper type) but are special airflow control devices (e.g. Phoenix valves) due to the local oversight agency\'s (OSHPD\'s) stringent room relative pressure requirements and lint issues for standard VAV terminals on the exhaust side. Such control devices are considerably more expensive than standard VAV terminal units. Therefore we request confirmation that the following clarification (for hospitals only) of 90.1-2004 section G3.1.1 exception C provides a suitable baseline in accordance with the intent of LEED" "It appears that the applicant is requesting the use of a constant volume baseline HVAC system. As is noted in the request, several rooms in a hospital have special pressurization and/or cross-contamination requirements that can not be adequately met by a VAV system. These spaces, however, satisfy the requirements of Exception (c) to Section G3.1.1 of ASHRAE 90.1-2004 and the baseline HVAC system may be modeled as System 3 - packaged single zone air conditioner (PSZ). The description of System 3 in Table G3.1.1B indicates that the fan control is ""constant volume."" Therefore, it appears that the system requirements outlined in Section G3.1.1 adequately address the design conditions and allows for the use of constant volume systems for the spaces in question. In addition, widely-available building simulation programs (such as DOE-2.2) do allow dehumidification control with PSZ systems. Thus, the PSZ system can modeled as a constant air-volume system that overcools and reheats to meet required humidity levels." "None" "None" "LEED Interpretation" "2471" "2009-02-20" "New Construction, Commercial Interiors, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "We are pursuing LEED NC for a high end high rise residence in Tokyo, Japan. We are showing compliance for EA-P2 and energy cost reduction for EA-C1 using the Performance Rating Method (Appendix G - PRM). ASHRAE 90.1 requires that the ratings for fenestration U-values, SHGC, and VLT are determined in accordance with NFRC 100 and 200. We will be using double paned and double paned Low E flat glass produced by AGC (Asahi Glass Co) here in Japan. AGC is one of the largest flat glass manufacturers and the parent company of AGC Flat Glass North America (formerly AFG - American Flat Glass). As this is a very high end residential project, with large glazed surfaces, a great deal of attention was paid to specifying glass in the design. Our issue is that AGC Japan products are rated using the Japanese Industrial Standards (JIS) and not NFRC as required. Although not explicitly stated in Appendix G - PRM, it is our understanding that if products are not NFRC rated, the poor default values provided in Normative Appendix A (Tables A8.1 and A8.2) of ASHRAE 90.1 are required to be used in place of manufacturer provided data for modeling purposes. NFRC rated products are not available in the in Japanese market. We have contacted AGC Japan to inquire if they have knowledge of NFRC rating procedures. Their response was that they do not, and only rate to JIS standards as required in Japan. The Japanese Industrial Standards (JIS) used for determining the solar optical and thermal properties of windows are JIS R 3106 and JIS R 3107. These two standards are stated by the Japanese Standards Association as being equivalent to ISO 9050 (Glass in building - Determination of light transmittance, solar direct transmittance, total solar energy transmittance, ultraviolet transmittance and related glazing factors) and ISO 10292 (Glass in building - Calculation of steady-state U values of multiple glazing). We understand that ISO 9050 and ISO 10292 form the referenced technical basis for ISO 15099 (Thermal performance of windows, doors and shading devices - Detailed calculations) which is the technical standard for determining optical and thermal properties of fenestration assemblies. ISO 15099 in turn defines the technical basis of NFRC 100 and NFRC 200. Other than the requirement for fenestration products being tested in a NFRC approved laboratory, which do not exist in Japan, we believe the JIS rated properties provided by AGC are in compliance with the technical requirements of NFRC standards and thus ASHRAE 90.1. Given this we have the following questions: 1) Can we use optical and thermal properties provided by AGC for Japanese domestically produced flat glass to model performance compliance in eQuest/DOE-2 using the performance rating method? 2) If 1) above is unacceptable, can we substitute optical and thermal properties of similar AGC NA (AFG) glass products for the eQuest/DOE-2 simulations? If the above is unacceptable, we have not identified any other way around this issue other than to import glass or have glass tested in the U.S. Both of these options are costly and not practical, and would deter this and any future LEED NC projects from being undertaken in Japan. In addition, we believe importing from abroad is not environmentally preferable in terms of CO2 impacts associated with transport." "The applicant is requesting the use of optical and thermal properties for fenestration determined by standards other than NFRC 100 and NFRC 200. The Japanese Industrial Standards (JIS) appear to be technically equivalent to the NFRC standards referenced in ASRHAE 90.1-2004. The use of optical and thermal properties determined by JIS 3106 and 3107 represent the actual thermal performance of fenestration products and may be used to determine fenestration parameters for use in the energy simulation. Please note that the NFRC ratings refer to the optical and thermal properties of the whole assembly. When preparing the EAc1 submission, the applicant should confirm that the optical and thermal properties determined by the applicable JIS standards and used in the energy simulation represent the properties of the whole fenestration assembly. Applicable Internationally; Japan. " "None" "None" "X" "LEED Interpretation" "2475" "2009-02-09" "New Construction" "EAc1: Optimize Energy Performance" "REQUEST: This CIR is requesting approval of a proposed Exceptional Calculation Methodology (ECM) for energy savings in a manufacturing process. INTRODUCTION: The Project consists of a 188,597 ft2 snack food manufacturing facility. The project comprises office, warehouse, and manufacturing that includes extensive oil frying and baking equipment necessary to process salty snack products. Energy required for the manufacturing process exceeds 92% of the facility\'s total energy load, with over 90% of this energy in the form of natural gas. Pursuant to the Credit Interpretation Ruling established by USGBC and EA TAG for NCv2.2 EAc1 dated 08/13/2007; since the industrial energy use associated with specific manufacturing processes are not covered by ASHRAE 90.1-2004, an alternative compliance path must be established. APPROACH: Per EAc1 CIR requested on 7/20/07 and a ruling dated 8/13/07, an alternative compliance path will be established for the manufacturing space using an ECM as described below. Please verify that the following Exceptional Calculation Methodology may be used for the energy baseline and the design project process loads. PROPOSED COMPLIANCE PATH: 1) Energy Baseline Model - Manufacturing Process Load The Project Client is currently recognized as the industry leader in batch kettle manufacturing and supplies the nation\'s largest salty snack company with private branded product. While unique in it\'s large implementation of this process, the Project Client has verified all energy analysis and baselines as listed below using modeling tools created by this largest salty snack manufacturer, as a means to establish standards (over 38 plants in North America) for the amount of energy necessary to convert potatoes and corn raw materials into the suggested salty snack products. In this comparison, the Project Client has established that the historical operational data used for the baseline calculations, as described below, falls within percentage points of the aforementioned standard models. When combined with the Project Client\'s existing mature energy management program and industry new equipment, this presents the baseline as a fair and conservative representation of industry standards and best practice in energy consumption from which reductions are to be created for LEED certification. We would compared with the project design with an existing manufacturing facility that has identical processes and climate coditions, similar envelope and the same industry standard new equipment. Project Client has established the natural gas baseline model using historical operational data at the existing facility over the fiscal year 2008. Existing plant operations monitor and record energy per pound of product over time utilizing sub-meters and HMI (Human Machine Interface) software that provides discrete consumption measurements of energy for individual process lines. These measurements have been verified through stack readings to establish combustion efficiencies and energy consumed per line and per pound of product produced. 2) Design Process Load and Energy Savings: The design project equivalent is established as a measure of natural gas efficiency expressed as Btu\'s of energy per pound of product manufactured (Btu/lb). This calculation also includes the volume of energy necessary to condition and exchange the air necessary to support these manufacturing. Production rates in total pounds per process will be used to model the equivalent amount of energy required in Btu\'s/lb, and will represent the necessary reductions in energy use. Electrical baseline usage is established through historical data for the comparison facility over the fiscal year 2008. The equivalent is established as a measure of KWh per pound of product manufactured (KWh/lb). Design connected electrical load for manufacturing equipment at project site calculated to same as baseline due to identical and energy equivalence of industry standard new equipment specified." "The applicant is proposing an alternative compliance path for a process dominated snack manufacturing plant. The proposed approach appears to be reasonable. The applicant should note however, that to pursue credits under EA credit 1 all calculations must be converted to total energy cost (of natural gas and electricity consumed). While the energy per pound of product may be a metric for efficiency, it does not qualify for points calculations. The applicant must also provide the following information at a minimum to gain the points: 1. Detailed narrative description of the processes taken credit for 2. Detailed narrative and back up data for determining the baseline energy consumption 3. Narratives and cutsheets of the proposed new equipment clearly highlighting the efficiency metric for each piece of equipment credit is claimed for. The applicant should also note that since this project is process energy dominated, it will only qualify for a maximum of 4 points from the process energy efficiency side. *Please note (added 10/15/2009)*: Projects are now eligible to claim more than 4 points from process energy efficiency savings. This guidance supersedes CIR 2/9/2009 which placed 4 point maximum limit on process energy savings. Applicable Internationally. " "10291" "None" "X" "LEED Interpretation" "2483" "2009-07-16" "New Construction" "EAc1: Optimize Energy Performance" "The project team is seeking guidance on the preferred energy modeling approach for our project. The project has a central boiler plant that serves the entire existing building and will be upgraded to serve the addition and renovation that are included in this project. A separate cooling system is being installed that is completely isolated from the system serving the existing facility. One new air handling unit serves a renovated area, part of a new addition and an existing area that is not included in our project ""LEED Boundary"". Our request focuses on the approach to modeling this air handling unit. We intend to model the boiler plant as a district energy system per the document published by the USGBC, ""Required Treatment of District Thermal Energy in LEED-NC Version 2.2 and LEED for Schools"", following Steps 1 and 2 as appropriate. We intend to model the new cooling system as designed, as an independent system (i.e. not part of a DES) since it serves only areas within the ""LEED Boundary"". We intend to include all areas within the building that are served by the new equipment, including the spaces that are not affected by any other work, which are excluded from our project ""LEED Boundary"" in other credit calculations. Furthermore, we intend to exclude the existing portion of the building that is not being affected by the project work, which is also excluded from our ""LEED Boundary"". Per Appendix G, Table G3.1, Section 2 Additions and Alterations, ""It is acceptable to predict performance using building models that exclude parts of the existing building (sic) provided that all of the following conditions are met: (a) Work to be performed in excluded parts of the building shall meet the requirements of Section 5 through 10. (b) Excluded parts of the building are served by HVAC systems that are entirely separate from those serving parts of the building that are included in the building model. (c) Design space temperature and HVAC system operating setpoints and schedules on either side of the boundary between included and excluded parts of the building are essentially the same. (d) If a declining block or similar utility rate is being used in the analysis and the excluded and included parts of the building are on the same utility meter, the rate shall reflect the utility block or rate for the building plus the addition (sic). It is the project team\'s understanding that each of these conditions will be met by the model as described below: (a) No work will be included in excluded parts of the building. (b) Excluded parts of the building are those served by separate HVAC systems. The area that is served by a common HVAC system that is being installed as part of the new work will be included. (c) Design space temperatures, operating setpoints and schedules are essentially the same, as the entire building is occupied by the same tenant. (d) The utility rate structure used in the analysis and the energy savings calculations will comply with this requirement. In summary: 1) Appendix G states that excluded parts of the building must be served by separate HVAC systems. 2) The LEED Rating System and each CIR that has been submitted follows a common theme of ""Whatever is within the ""LEED Boundary"" must be accounted for within each credit. 3) We need the review team to determine whether it is necessary to change the ""LEED Boundary"" to include the areas served by the new AHU that are NOT being affected in any other way. If it is determined that it is not necessary to change our ""LEED Boundary"", we would like the review team to determine whether it is acceptable to model the building as designed within our ""LEED Boundary"" and also include the portion of the building served by the new AHU in order to be in compliance with Appendix G. This area would not be included in other ""LEED Boundary"" governed credit calculations." "The applicant is requesting clarification on how to account for a new air-handler that serves the LEED project as well as some areas outside the project\'s LEED boundary. It is essential to model the entire system including areas within and outside the LEED boundary. Thereafter post-processing based on prorating HVAC energy use between existing and new areas could be done in accordance with LEED-CI requirements - modeling procedure and requirements are in the reference guide. To determine the reduction in annual costs for the project area, the evaluation needs to consider the entire building area that is served by the HVAC plant serving the project. This situation will only apply to cases where a building that is certifying the addition/whole building (pursuing LEED), and the AHU that serves the new addition also serves part of the existing building that is not pursuing LEED certification; it does not apply to partial building renovations. Please note, for the LEED NC certification to apply to the entire building, the entire building must be modeled. If the project is trying to certify the separate addition only, then the pro-rated modeling methodology mentioned above can apply provided that the project title clearly identifies the project as an addition. Administrative NC 2.1 / 2.2 CIR dated 5/23/2007 The following requirements of Appendix G need to be considered based on the size of the air handler and building area, as if the entire area served by that air handler were included: G3.1.1- Baseline HVAC Systems G3.1.2.10 - Exhaust Air Energy Recovery G3.1.2.6 - Economizers (2004 version only) G3.1.2.1 - Equipment Efficiency G.3.1.2.9 - Fan Power (2004 version only) Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2485" "2009-02-23" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a new 135,000 sf office and classroom building on the University of Iowa campus. The building is served by the University\'s combined heat and power plant. (UI-CHP) The project requires that we follow the LEED NC 2.2 CHP methodology Case 3. The CHP methodology document requires certain qualifications for the combined heat and power plants. Specifically, Qualification 2 requests a narrative addressing emissions and demonstrating that the environmental impact of the system is lower than if the building heating requirements are met with an 80% efficient gas boiler and cooling requirements are met with baseline cooling systems using electricity provided from the local grid. In this case, the University of Iowa measures the emissions and is required to file an annual emissions report every year with the Iowa DNR. This report details emissions for SOx, NOx, CO2, and particulates. These same emissions are available from the local utility that would otherwise provide power to the building. On-site gas firing emission data from The Climate Registry General Reporting Protocol Version 1.1. We propose to use the report required by the Iowa DNR that documents the emissions from the University plant as well as the emissions data provided by the Utility to evaluate the project with respect to LEED NC 2.2 CHP methodology Case 3, Qualification 2. UI-CHP emissions for the building will be calculated as: Cooling energy use BTUs from Proposed Model x UI-CHP emissions per BTU + Heating energy use BTUs from Proposed Model x UI-CHP emissions per BTU Utility and on-site heating and cooling related emissions will be calculated as: Cooling energy use BTUs from Proposed Model with baseline cooling system x Utility emissions per BTU of electricity at site + Heating energy use BTUs from Proposed Model with 80% efficient gas boilers x Emissions per BTU of gas firing We will compare the UI-CHP emissions with the Utility and on-site heating and cooling related emissions for each metric (SOx, NOx, CO2 and particulates) to determine that UI-CHP has a lower environmental impact. Is this approach acceptable?" "The applicant wants verification for the process of calculating GHG Emissions. The process is based on mandatory reporting required by the Iowa DNR and therefore is acceptable. The applicant must provide the referenced emissions reports as part of the submittal. Please include a brief narrative to explain the process and cross reference this CIR ruling." "None" "None" "LEED Interpretation" "2527" "2009-04-14" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "We seek approval of the following energy analysis approach for a project registered under LEED-NC v2.2, after June 26, 2007. The project is a ballpark located in Climate Zone 5A. A majority of the concession stands and restrooms located on the concourses will only be used for ballgames from April through September. Traditionally, space unit heaters are installed for freeze protection of the plumbing systems and building finishes during unoccupied periods. These unit heaters would have a heating output between 3.4 Btu/h ft2 and the maximum allowance of 15 Btu/h ft2 listed in Table 3.1 of ASHRAE/IESNA Standard 90.1-2004, so the spaces would technically be considered semiheated. The spaces would be maintained at a minimum setpoint of 45 degrees F to ensure that none of the pipes freeze. We are considering implementing an energy conserving operational procedure. The plumbing systems would be drained down during the off-season from October through March when freeze potential exists. This practice requires special design consideration for ease of the drain down procedure. The concession stands and restrooms would require no space heating equipment, thereby eliminating space heating energy. The drain down practice requires special effort from building operations staff, and we believe that a commitment to such effort warrants consideration in the energy analysis. The energy savings are quantifiable and provide an environmental benefit. The drain down practice allows elimination of additional insulation and building materials that also provides an environmental benefit. Therefore, we propose to classify these concession stand and restrooms located on the concourses as semiheated spaces. The baseline insulation would be modeled as semiheated; the baseline heating setpoint would be modeled at 45 degrees F. The proposed spaces would be modeled as unconditioned." "The applicant is proposing that the proposed design be considered an unconditioned space in the energy simulation due to the application of a drain down procedure. The proposed approach is not acceptable. ASHRAE 90.1-2004 Table G3.1 Number 10(c) states that an electric heating system must be modeled in the proposed case even if a heating system is not provided in the baseline case. Note that several CIRs address modeling requirements of unconditioned and semi-heated spaces, including a CIR dated 10/3/2008 that confirms unconditioned spaces must be modeled with a heating system." "None" "None" "LEED Interpretation" "2544" "2009-04-15" "New Construction" "EAc1: Optimize Energy Performance" "Approximately 93% of the building in the Seal and Sea Lion Life Support System project, a remodel and addition to an existing facility, is dedicated to equipment spaces furnishing treated and cooled seawater to pools for pinnipeds. Approximately 90% of the total building energy consumption is for process loads related to these aquatic systems, overwhelming thermal envelope, HVAC, lighting and other miscellaneous power loads. Using the conventional approach outlined in ASHRAE 90.1-2004 Appendix G (to implement energy saving strategies and assuming identical process loads for both the baseline and proposed designs) will not demonstrate sufficient reduction in process energy to achieve the LEED EAc1 two-point-minimum. The team proposes including regulated HVAC and lighting loads, and modeling only the systems that serve occupied spaces, then following the Exceptional Calculation Method for ASHRAE Std. 90.1 G2.5 (outlined in the LEED NCv2.2 reference guide and in the CIR ruling dated 10/24/08) to document measures that reduce process loads. Our intent is to take credit for process load reduction to comply with the minimum energy requirements for a renovated building. To demonstrate the evaluation of process load savings we intend to submit a comparative summary of annual savings for energy use relative to discharge piping, equipment variables and chilling water. Historical trend data may be available for chilled water, and if so could be used as the baseline. If historical data is not available, ASHRAE design data for the average cooling day will be used as a baseline. Historical trend data for other process loads is not available. The following assumptions regarding energy use and cost for process loads in the baseline and proposed cases will be made: I. Seawater cooling systems (offset solar gains and maintain 68 deg F temperatures for six pools) A. Baseline case: 1. Rooftop air-cooled chillers furnish refrigeration for chilled glycol solution circulated to shell-and-tube heat exchangers. 2. Pumps deliver constant flow rate to shell-and-tube heat exchangers. 3. Three-way control valves modulate chilled glycol solution to maintain pool temperatures. B. Proposed case: 1. Rooftop air-cooled chillers furnish refrigeration for glycol solution circulated to plate heat exchangers with less pressure drops to reduce pumping energy. 2. Pumps with variable frequency drives deliver variable flow rate to plate heat exchangers, yielding less horsepower with pressure drop reductions. 3. Chilled glycol solution piping incorporates a decoupler to assure chiller minimum flow during partial load conditions to optimize chiller turndown performance. 4. Two-way control valves modulate chilled glycol solution to maintain pool temperatures. II. Seawater treatment systems A. Baseline case: 1. Pumps controlled by throttled valves maintain target flow rate. 2. Pipe and valves sized per Hydraulic Institute standards for fluid velocities of 8 feet/second. 3. Sand filters backwashed after a 10 to15 psi pressure differential is attained per manufacturer recommendation. 4. Design pools to match dimensions of existing pools. The zoo\'s requirement is to maintain volume to match existing pools. B. Proposed case: 1. Pumps controlled by variable-speed drives to maintain target flow rate. This reduces pump operational energy an estimated 15%. 2. Pipe and valves sized for fluid velocities of 4 to 6 feet/second. This reduces waste energy due to friction and reduces installed pump horsepower. 3. Sand filters backwashed after an 8.5 psi pressure differential is attained. This reduces energy consumption due to filter head loss an estimated 10 to 20% and reduces installed pump horsepower. 4. Design pools with reduced water surface area and increased depth to maintain required volume. This reduces chilling demand due to solar radiation/convection/condensation at the water surface an estimated 30%. Are the proposed assumptions, data sources and methodology acceptable for demonstrating credit compliance?" "The applicant is requesting confirmation of assumptions used to develop an exceptional calculation methodology (ECM) related to reduction of process loads. Insufficient information has been provided to clarify how the baseline mechanical systems have been selected. All assumptions, background data for assumptions (if available), and calculations should be provided during the review process to improve the probability of ECM approval. Some direction is provided for the following: Throttled valves: no frictional losses; no credit to be claimed for surface area. Sand filters: agree on this point Change rate/ turnover of water - will have to be equal; similar to building envelope As a matter of general guidance: The fluid handling systems should comply with Section 6.5.4 Hydronic Cooling and Heating Systems with respect to coil valves (2 or 3 way), pump operation, etc. Larger pipe sizes (lower velocities) are a good way to reduce system energy use." "10291" "None" "LEED Interpretation" "2550" "2009-04-14" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1.3: Optimize Energy Performance, HVAC" "Background: Our project is a 3 story, 16,500-sq.ft. addition to an existing 3 story, 84,000 sq.ft. building. The existing building is predominately laboratory space with some office space. The addition will be of similar use. The heating and cooling of the existing building is served by a central utility plant which provides chilled water and hot water via a steam boiler and heat exchanger. It is proposed that the addition also be served by the central plant. The central plant serves several other buildings on the site as well. In order to make a decision on whether we would like to obtain LEED registration on just the new addition or on the entire building with the new addition, a preliminary building simulation is being modeled. For the ASHRAE baseline, the system is modeled as a ""System 3 - PSZ-AC"" (packaged rooftop, constant volume, direct expansion, and fossil fuel furnace) per table G3.1.1A of ASHRAE 90.1-2004. Though the combined building size would categorize building with addition as a ""System 5 - Packaged VAV w/ Reheat."", section G3.1.1(c) mandates conforming to the requirements of System 3 as an exception due to the special pressurization relationship/ cross-contamination requirement of the laboratory. Interpretation Request: Little is stated in ASHRAE 90.1 2004 on the most appropriate way to model a system that has chilled water and hot water heat supplied from a central plant. However, there are a few CIRs concerning similar circumstance that allude to it such as the 1/27/2004-2/24/2004 EA1.1 CIR. In it, it is stated that ""While the situation described is not using purchased chilled water or steam, this HVAC description for the budget building is the closest to the proposed design and should be used for the energy modeling purposes."" This approach for the budget building model is quite workable since the building owner has costs available for both chilled water and heating hot water. However, the baseline is modeled as a DX cooling and gas fired furnace. Is it appropriate to model the budget building with chilled water and heating hot water, when the baseline model is using neither of these? If not, how should the baseline and budget building be modeled?" "The applicant is requesting clarification regarding modeling methodologies for projects which include a central utility plant. Note that the USGBC published a document titled ""Required Treatment of District Thermal Energy in LEED-NC version 2.2 and LEED for Schools"" in May of 2008 located at the following website: http://www.usgbc.org/ShowFile.aspx?DocumentID=4176 Please refer to this guidance document, which is also referenced in a CIR dated 5/28/2008. Also note that the exception in ASHRAE 90.1-2004 Section G3.1.1 Exception (c) is only applicable for zones that have special pressurization requirements. All zones of the building or addition that do not meet the exception requirements must be modeled using System 5 - Packaged VAV w/ Reheat in the baseline. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2555" "2009-04-14" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "We are working on this LEED NC 2.2 project in Beirut, Lebanon. To secure the minimum mandatory 2 points under EA Credit 1, we need to follow Option 1 - Thermal Modeling Simulations as it is the only available option for buildings above 100,000 square feet. After a lot of time spent attempting to gather local climatic data, we were unable to obtain a proper Weather Data File for Beirut which is fully accurate, has all the necessary climatic parameters, and is usable to undertake Option 1 Thermal Modeling Simulations. This is due to the last 35 years of unstable political situation / war in the country, resulting in a lack of proper weather data tracking and monitoring. Is it acceptable in such circumstances to select another city in the region with a very similar weather pattern, and use its weather data file for the simulations? We have selected the city of Larnaca, in Cyprus as in our opinion it represents the closest proxy for Beirut given the following: 1) Same climatic classification - Zone 3 as per ASHRAE 92.1 2) Same Mediterranean climate 3) Coastal city as Beirut 4) Its proximity to Lebanon 5) Very close latitude as Beirut: The latitude of Beirut is 33" "The project has requested clarification regarding the use of an alternative weather file for a location that does not have weather data. Based on the given circumstances, it is an acceptable approach to select a weather data file that closest resembles the project location in climatic classification including average temperature, climate conditions, and latitude. Due to improved resources and computer simulation tools, it is possible to customize a weather file for a location. Some resources can be found here - http://apps1.eere.energy.gov/buildings/energyplus/cfm/weatherdata/weather_request.cfm and http://apps1.eere.energy.gov/buildings/energyplus/weatherdata_sources.cfm Applicable Internationally; Lebanon; Cyprus." "None" "None" "X" "LEED Interpretation" "2557" "2009-04-14" "New Construction, Existing Buildings, Commercial Interiors, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "This project is to renovate 300,000 square feet of an old factory and convert to a distribution center. The owner strongly desires to be sustainable and will use many sustainable features whether or not LEED certification is sought. We will use high efficiency lighting and high efficiency infrared heaters, but no cooling. If we use the ASHRAE appendix G, we have to model the baseline cooling system for the baseline and the proposed. Since the cooling energy will be much larger than the heating energy the 14% reduction from ASHRAE will not be possible. This force the project to be penalized for energy never actually used. In this case we feel that the ASHRAE standard does not rationally apply. This project will reuse a large facility and incorporate significant sustainability features and we would not like to be excluded because the ASHRAE standard does not apply logically to this facility. Is there any alternative method for compliance in this situation?" "The project has requested clarification regarding the use of the ASHRAE Baseline requirements in Appendix G. Although a cooling system must be modeled in both the Baseline and Design case, there are no requirements for Temperature Setpoint. Therefore, both cases may have the Cooling Temperature Setpoint elevated such that both systems do not ever run and thus does not consume any energy. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2558" "2009-05-26" "New Construction, Commercial Interiors, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "Background: Our project consists of a 4-story office building approximately 105,800 square feet in area. The building will be conditioned by a variable air volume system which includes a single, custom penthouse air handling unit on the roof. The project has been designed to meet ASHRAE Standards 62.1-2004 and 90.1-2004 including the application of demand controlled ventilation strategies. Each temperature control zone will include a series fan-powered terminal unit with electric reheat and each is equipped with an ECM motor. While the basic benefits of ECM motors include motor efficiencies nearly twice that of a traditional PSC motor, negligible heat gain from the motor to the airstream, and the ability to perpetually maintain a given supply airflow, the ability to modulate the terminal fan via the building automation system (BAS) is now feasible allowing control strategies never before possible. Series fan-powered terminal units have traditionally operated at a constant airflow during occupied periods. The proposed terminal unit control strategy for this project includes multiple, unique operating airflow levels: 1. During cooling demand, the fan will operate at the maximum cooling airflow condition (while the primary air damper modulates). 2. Under no call for heating or cooling, the fan will slow to the ""deadband"" airflow of approximately 50% of the peak cooling airflow. 3. At initial heating demand, the first stage of reheat will be energized and the terminal fan will increase to the first heating airflow setpoint. 4. On a call for additional heat, the second stage of reheat will be energized and the terminal fan will increase to the second heating airflow setpoint, and likewise with the third and final stage of reheat. Note that the heating airflow setpoints are specifically calculated to result in a consistent discharge temperature of 83F for optimum diffuser performance and blending in the space. Intent: Develop a strategy that accounts for the energy savings provided by series fan-powered terminal units with ECM motors. Proposed Strategy: A Whole Building Simulation and energy analysis has been performed towards LEED certification via the Building Performance Rating Method and in accordance with Appendix G of Standard 90.1-2004 utilizing the Trane Trace 700 analysis software (v6.1.3). In detailed review of the program input tables and output reports, we determined that the software was unable to model the control strategy proposed above. This was confirmed via direct communication with the software engineers. Through additional research, we further understand that Carrier HAP, EQuest, nor any other DOE-2 based energy simulation program has the algorithms or capability required. We are requesting confirmation that the following strategy conforms to the modeling requirements of Appendix G. 1. Utilize the Trace 700 energy program to perform a complete building analysis determining all energy consumption for both the proposed building and baseline comparison building in accordance with Appendix G. 2. Apply the Exceptional Calculation Method specifically and only to the terminal fan energy consumption as allowed by Paragraph G2.5 of Appendix G. The Exceptional Calculation Methodology will be as follows: a. Energy savings will be calculated for each individual terminal fan size and at each reduced operating speed based upon the manufacturers fan power data. b. Operating run time at each fan speed within the proposed control strategy will be determined using the heating and cooling load profiles from the Trace 700 output reports. c. Fan terminal energy savings will be calculated by multiplying the run time of the fan by the reduction in KW of fan energy at each specific operating condition. d. The terminal energy savings will be subtracted from the Trace 700 simulation output summary. Is the proposed strategy acceptable?" "The project has requested clarification regarding the use of a specific method of computing the additional savings of using Fan-Powered Boxes with a 3-Stage Heating Coil and Electronically Commutated Motors (ECM motors) over traditional PSC motors. This approach is valid and acceptable, but more detailed information must be provided on how fan run time is determined at each of the three heating stages. The motor efficiency should be verified for each airflow condition chosen in the post-processing. Hourly simulation tools such as Trace 700 use complex computation routines and these should be accounted for in any hand calculations that are used to substitute for a Trace 700 energy simulation. Specifically, simply assigning the fans to run at full load (where they are far more efficient than their traditional PSC counterpart) continuously for a large portion of a season (i.e. peak heating months) would not be accurate. To calculate savings for ECM motors the following analysis should be done in the energy model to show compliance with ASHRAE Standard 90.1: " "None" "None" "X" "LEED Interpretation" "2559" "2009-07-20" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a new industrial building in Suzhou, China. The project consists of 8,000 2 of office area and 49,587m2 of production area. The production area includes welding machines, cranes, assembly and painting machines. The electricity required by the process machines represents approximately 60% of total energy cost. According to LEED NC 2.2 Reference Guide, project teams may follow the Exceptional Calculation Method to document measures that reduce process loads. Pursuant to EAc1 CIR posted on 9 May, 2008, the process loads would be firstly modeled identically in the Baseline and Design Cases, using ASHRAE 90.1-2004 Appendix G Performance Rating Method, and then the manufacturing portion will be modified in a proposed Exceptional Calculation Method. Those two energy saving results will be combined to fill out the EAc1 Submittal Template and come up with overall cost savings for the whole project. The CIR is looking for verification on the methodology used in Exceptional Calculation to calculate the process loads of baseline and design cases Process Baseline Case: The welder machine A in the baseline is a standard welding machine in this industry and is widely used. Welder A is very reliable and last more than 20 years. The project owner has purchased hundreds of welder A and has used them in most of global factories, including Cat Peoria, Ill., Cat Decatur, Ill., Cat Aurora, Ill., Cat Joliet, Ill., Cat Atlanta, Georgia, Cat Minneapolis, Minnesota, Cat UK - Peterlee, Cat Work Tools, Kansas, Cat Mexico, Monterrey, Cat Brazil - Piracicaba, Cat China - Xuzhou, etc. The performance of welder A will be evaluated based on factory testing. Process Design Case: A brand new welder named welder B will be applied in design case, which is capable of saving considerable amounts of input powers. The machine was designed from the ground up for our client\'s specific application, so the market penetration now is zero. Welder B was tested exactly in the same way as Welder A. The testing result shows that the idle watts and arch input power of Power+ are all lower than welder A. Calculation: Given the same local electricity utility rate and same operation schedule (12 hours of arc hours and 12 hours of idle hours per day, 250 working days per year), the difference between annual electricity consumptions of welder A and B would be the process energy saving. Credit Interpretation Request: Please confirm that our assumptions and methods for calculating the process energy load for baseline and design case are acceptable for EAc1." "The description of the method for calculating and determining process energy savings appears reasonable. To be consistent with previous credit interpretation rulings, the submission documentation would need to follow guidance from EAc1 CIR ruling dated 02/09/2009. \n\nPlease note, the baseline should be established on the basis of the current industry wide practice and not the project owner\'s past practices. In addition, note that a maximum of 4 EAc1 energy points can be awarded for process energy savings. \n\n*Please note (added 4/1/2010)*: Projects are eligible to claim more than 4 points from process energy efficiency savings. This guidance supersedes CIR 2/9/2009 which placed 4 point maximum limit on process energy savings. Applicable Internationally; China. " "None" "None" "X" "LEED Interpretation" "2586" "2009-05-21" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "We are submitting under LEED for Schools, V2.0 two additions of 54,000 sf and 55,000 sf, to an existing high school of 150,000 sf in the City of Chicago. The two additions will be submitted for LEED certification as one project; the existing building will not be included in the LEED submission. The additions, which are separate from the existing building, are connected to the existing building by an interior pedestrian link. These links are designed as entrance vestibules between the existing building and the additions. A central plant in the existing building generates hot water via boilers and chilled water via air-cooled chillers. This central plant will be upgraded to provide cooling and heating for the new additions and the existing building. The existing heating and cooling plant equipment will be upgraded. Two additional condensing boilers will be added to the boiler plant. The existing chillers are near the end of their service life, and they will be replaced. The existing AHU\'s in the existing building will remain and will serve the existing building only. Seven new air handling units will be added with the new additions and will serve the new additions only. Therefore, given that the two new additions are satellite buildings served by the central plant located in the existing building, we will model the energy use of the new additions according to the USGBC\'s document "" Required Treatment of District Thermal Energy in LEED for Schools"", version1, dated May 28, 2008. We are proposing to upgrade the upstream equipment to make it more efficient and to install high efficiency downstream terminal equipment in the new additions. All new work, including replacement of plant equipment and distribution will meet or exceed the HVAC system prescriptive requirements of ASHRAE 90.1-2004, and the ""Required Treatment of District Thermal Energy in LEED for Schools"". Given the above information, is it acceptable to do the EAp2 and EAc1 energy model and all other EA prerequisites and credits following the District Thermal Energy reference document for compliance with the EA prerequisites and credits?" "Given the above project information, this LEED for Schools project contains a District Energy system (DES) and is required to follow t he requirements and direction of the document ""Required Treatment of District thermal Energy in LEED for Schools."" As stated in the document, ""This document defines requirements that apply to all such district energy systems, whether new or pre-existing, or whether owned by the project building\'s owner or another entity."" Following the requirements of the District Thermal Energy document for this project is an acceptable and required approach. Applicable internationally. " "None" "None" "X" "LEED Interpretation" "2620" "2009-06-04" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "The question is based on ASHRAE 90.1 requirements for Performance Rating Method for building modeling. This building has very high internal loads with the baseline process load at 49% of the total building energy based on actual equipment. The internal load is primarily computer desktops and monitors. Both baseline and proposed building energy usage numbers are based on a calculation worksheet as published by the US dept of Energy for computer desktops and monitors. The Energy Star usage value increases the proposed energy building performance reduction by 10-15%. This lower value for the process load is still above the 25% requirement for the total building energy amount as outlined in the LEED requirements of this point. The equipment in the new building that the owner will provide will consist of Energy Star computer desktops and monitors. We request clarification that we can run the baseline with standard energy load based on LBNL 2007 standards and proposed building with Energy Star energy loads." "The applicant is requesting clarification on how to account for energy savings due to Energy Star rated equipment. Plug in equipment falls under the Process Loads category and any savings claimed under process loads have to be taken as an Exceptional Calculation. Please model the same process loads in both the baseline and proposed building. Then run a separate run of the proposed building with the Energy Star rated equipment. Report savings from this run Exceptional Calculation table in the LEED Submittal Template. Be sure to include a detailed narrative with all assumptions and supporting calculations with the submittal. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "2622" "2009-07-30" "New Construction" "EAc1: Optimize Energy Performance" "Question: We would like to confirm that our HVAC energy modeling strategy in our Vivarium areas is acceptable to USGBC. In particular we would like to confirm our baseline model and associated assumptions will be accepted. ASHRAE 90.1-2004 does not clearly address Vivarium requirements. We feel that laboratory references are the most applicable. One large difference between Laboratory and Vivarium design is that current industry standard for Vivarium design is constant volume air systems. This results in not being able to meet turn down requirements published in ASHRAE 90.1-2004. Project Description: Our project is a 217,900 square foot vivarium with integral boiler and chiller plant. The facility includes the following functions: Vivarium (approx. 55% of program area) Vivarium Support (approx. 15% of program area) Laboratory (approx. 10% of program area) Laboratory Support (approx. 5% of program area) Office (approx. 15% of program area) Mechanical / Electrical Rooms Mechanical Penthouse Baseline Model - Vivarium and Vivarium Support Air Side System Description: Air System - 100% outside air constant volume reheat system with 50% effective heat wheel.  A minimum of 15 ACH (air changes per hour) is utilized due to room occupancy and ammonia odors. 10 - 15 ACH is referenced by ASHRAE and the Guide for the Care and Use of Laboratory Animals. This air change rate is heavily influenced by animal density, animal size, species, type of bedding, and frequency of bedding change out. Our project has concluded that 15 ACH is the correct air change rate for our application during heavy room occupancy.  ASHRAE 90.1 - 2004, chapter 6.5.7.2 requires constant volume systems to have heat recovery with 50% effectiveness. This limits available technology to heat wheels. Heat wheels are known to pass ammonia odors. For this reason we do not feel it would be logical to model the heat wheel if it is not a realistic option for a baseline design. Can the submitted model be based on a 50% sensible effective run around glycol heat loop in lieu of a 50% effective heat wheel? Proposed Model - Vivarium and Vivarium Support Air Side System Description: Air System - 100% outside air variable volume reheat system with 50% effective sensible run around glycol heat loop.  Unoccupied: 4 ACH minimum with active control of airflow override due to high temperature, high CO2, and high ammonia levels. Temperature, CO2, and ammonia will be continuously monitored. Airflow will actively adjust based on contaminant concentration levels in each space. In this facility high room turn over will occur on a regular basis as studies start and finish. A significant amount of energy can be saved based on an unoccupied mode.  Occupied: 11 ACH - 15 ACH variable volume system. A significant amount of energy can be saved by reducing the airflow when space occupancy is low. In order to drop to 11 ACH we need to be assured that the environmental conditions in the room are acceptable. In this facility room occupant loading will be highly variable dependent on study. Some rooms will be very densely populated and others very lightly populated. We feel the best way to achieve an acceptable environmental condition is by monitoring environmental conditions (temperature, CO2, and ammonia) and actively modulating airflow between the minimum and maximum values to a desired set point." "The design team is requesting establishment of an alternate baseline, because the project feels that ASHRAE Standard 90.1-2004 is inadequate with regards to the energy modeling of a Vivarium. An alternate baseline has been proposed comparing a baseline constant volume system with heat recovery to the proposed variable volume system also with heat recovery. Generally speaking, Vivarium\'s are typically tied to laboratory spaces and can be considered under similar design conditions. The EPA has issued laboratory guidelines for modeling using ASHRAE Standard 90.1-2004 and 2007, and these guidelines do not allow an assignment of baseline systems based on perceived standard practices. Project team should follow ASHRAE 90.1 Appendix G with addenda. Hospitals, laboratories, vivariums have been addressed in Addendum ac to 90.1-2004. In addition, please provide supporting documentation and calc.ulations for determining the ACH during unoccupied and occupied hours for the proposed model. Applicable Internationally" "None" "None" "X" "LEED Interpretation" "282" "2001-09-05" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "For the Blanchard College Center project, we are asking the USGBC to clarify the criteria for declaring whether a building is New or Existing in relation to the available points for this credit. In the specific case of the Blanchard College Center, the project is primarily a gut renovation of an existing historical facility, to which two new additions will be added. The area of the existing facility is approximately 33,403 s.f. The area of the two additions totals approximately 13, 885 s.f. The additions therefore represent approximately 29.4% of the total building area. From a systems standpoint, approximately 95% of the existing shell will be reused, however, there will be new furring/insulation for the walls and roof, new lighting, and new mechanical systems. We are assuming that this facility qualifies as an existing building, primarily because the existing facility represents the majority of the overall square footage of the project. In addition, the efforts to preserve the form and shell of the existing building has restricted the designer opportunities to pursue more aggressive energy reduction strategies (e.g., building orientation, daylighting/ventilation strategies, high performance envelope, etc.). Please clarify that this is the correct assumption for this project." "THIS LEED INTERPRETATION HAS BEEN REVISED AS OF 9/21/06 TO PROVIDE A CALCULATION THAT IS MORE WIDELY APPLICABLE (AND IS EQUIVALENT FOR THIS SCENARIO). To calculate the optimization point table for a project that has both existing and new construction, use the following formula for each line of the table: target percent = (existing SF / total SF) * (existing percent) + (new SF / total SF) * (new percent) *This equation applies to LEED NC v2.0, v2.1, and v2.2 and LEED CS v2.0 ORIGINAL LEED INTERPRETATION 9/5/01: To calculate the optimization point table for a project that has both existing and new construction, use the following formula for each line of the table: existing percent + ((new SF / total SF) * 10) = target percent. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "3300" "2003-03-11" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "ASHRAE 90.1 does not allow credit for air leakage reduction. However, it does indicate that windows are allowed to have 1 cfm per square foot air leakage (at 0.30"" water.) The windows we are using in this project are very high performance, with significantly lower air leakage rates. The manufacturer has supplied test results indicating the tested air leakage rate. Further, we are using a blower door and infra-red camera simultaneously to locate and seal any air leaks in the window system that result from installation. We propose to take credit for this air leakage reduction, with the following methodology:\n\nThe tested air leakage rate at 0.30"" can be established for the windows as installed, based on manufacturer\'s data, and for the base case windows based on ASHRAE 90.1. Both these values will be extrapolated to expected winter heating season air leakage rate, using the LBL correlation for blower door test data. We have run two blower door tests, and will use the most recent (during which most of the air leakage has been taken care of) test data to establish the relationship between the air leakage rate at 0.30"" static pressure (75 Pa) and the average heating season air leakage rate, which is calculated at the building pressure established by the LBL correlation, which is based, in part, on the exposure of the building to wind. In this case exposure is significant, as the building is fully exposed on the west side of the building to windows ranging from south to west to north.\n\n We then propose to run the base case building, in the energy modeling, using TRACE, with the air leakage rate for the windows established in the above manner. The building as built would be modeled with zero air leakage rate. Preliminary estimates indicate that the difference in overall extrapolate natural air leakage rates in 0.04 air changes per hour, at typical heating season winter conditions.\n\n Blower door guided air leakage reduction: A significant effort at air sealing is part of the energy saving strategy for this building. With the location noted above, air leakage reduction is particularly important. Two blower door tests with simultaneous infrared scanning, have been completed. The first identified a number of areas that were not complete as designed. Most of these were completed by the time of the second test, and a number of areas were identified during the second test that, in my opinion, would not have subsequently been air sealed had this procedure not been in place. A list of further items was developed from this second air leakage test, and this list has been circulated by the GC to responsible parties, who will sign off when they have completed the items. When those items are complete, a third, and hopefully final, blower test will be conducted.\n\nWe propose to take credit in our energy calculations for the air leakage reduction between the second and third blower door tests, using the LBL correlation to extrapolate to typical heating and cooling season air leakage rates, as described in number 2 above. The extrapolated seasonal air leakage rate reduction would be applied to the base case building. For example, if the extrapolated air leakage reduction were 0.1 heating season air changes per hour from blower door test #2 to test #3, we would assign 0.1 ACH to the base case building and zero air leakage to the building as built.\n\nWe feel that this third round of testing and air leakage reduction is well beyond typical attention paid to air leakage, that air leakage control is particularly important in this very cold (7700 degree-day) climate and at this exposed site, and that we have demonstrated a method using accepted principals to quantify the savings. Blower door test results and LBL correlation spreadsheets for each test would be provided as part of the submission. We would also submit the list of items to be air sealed as part of the final air leakage reduction package.\n\n Windows and air leakage reduction together: We propose to add the two air leakage reductions - from window improvements and blower-door-guided air leakage reduction. For example, if the blower-door-guided heating season air leakage rate reduction were 0.1 ACH and the window air leakage reduction were 0.04 ACH, the base case building would be modeled at 0.14 ACH and the building as built at 0.0 ACH.)" "Advanced air sealing is a strategy that can lead to measurable energy savings, particularly in cold climates. Although this measure is outside the scope of ASHRAE 90.1 modeling protocol, you may be able to make a case for the significance of this strategy in improving energy performance. However, this will require clear and thorough documentation in order to be considered under the requirements of this credit.\n\n The following guidelines are provided to help strengthen your approach:\n\n(1) Provide manufacturer\'s air leakage test results that use the same testing protocol as that by which ASHRAE identified the baseline for window air leakage.\n\n(2) Use a typical infiltration rate as a baseline, and reduce it by the amount of improvement you can document or estimate from the air sealing strategies employed. Do not use zero infiltration in the model, as this is not a realistic assumption. A zero infiltration strategy would over-emphasize the percentage of overall energy use reduction represented by infiltration improvements.\n\n(3) Include required fresh air ventilation rates (per ASHRAE 62) in both the proposed and baseline model results.\n\n(4) Provide clear documentation of air sealing strategies and blower door test results, corrected for wind and temperature effects, to clarify anticipated air sealing performance.\n\n(5) Provide documentation which clarifies the percentage of energy savings attributed to the air sealing strategy, as opposed to other energy performance measures incorporated into the building.\n Applicable Internationally. \n\n **Updated January 1, 2014\n Advanced air sealing is a strategy that can lead to measurable energy savings, particularly in cold climates, though its effectiveness is especially dependent on the quality of construction and cannot easily be predicted during the design phase. Recognizing this, the ASHRAE 90.1 committee developed Addendum ag to Standard 90.1-2010, which establishes guidelines for claiming energy savings that result from reduced infiltration in Appendix G. The approved change allows credit only for buildings that complete envelope pressurization testing in accordance with ASTM E779. The appendix establishes a baseline air leakage rate of 0.40 cfm/ft2 (2.03 L/s•m2) at 0.3 in. wc (75 Pa) pressure differential compared to the measured leakage results in the proposed building.\n\n Projects wishing to claim energy savings from advanced air sealing may do so given they meet the following requirements:\n\n 1. Utilize Addendum ag to Standard 90.1-2010 to document savings.\n\n 2. Provide clear documentation of air sealing strategies and air leakage results from ASTM E779-10 Standard Test Method for Determining Air Leakage Rate by Fan Pressurization, including confirmation that all testing criteria defined in the standard have been met.\n\n 3. Provide documentation that clarifies how energy savings from reduced air leakage has been estimated from the ASTM E779 test results and identifies the percentage of energy savings attributed to the air sealing strategy, as opposed to other energy performance measures incorporated into the building. " "5060, 5691, 5456" "None" "X" "LEED Interpretation" "5017" "2006-07-05" "New Construction" "EAc1: Optimize Energy Performance" "Harvard Cowperthwaite Residence Hall, located in Cambridge, MA, is a six story, graduate student dormitory with 201 beds in 142 living units. The new building will include three levels of below grade parking, which has vehicle access at the grade level of the first floor of the residence hall. The above-grade portion is 102,036 SF and the below-grade portion is 106,307 SF, for a total of 208,343 SF. This new building is being constructed on the site of a grade level flat paved parking lot. The footprint of the garage is actually larger than the footprint of the residence hall to accommodate the college\'s parking needs. We intend to keep all of the garage within the scope of the LEED project, along with the residence hall. There will also be a 3-story wood frame residential building built above the footprint of the garage that is detached from the main 5-story residence hall. The three-story wood frame building is an additional 4,168 SF, with five additional beds in three apartments. This 3-story building will be supplied with heating hot water and chilled water from the plant in the 6-story building. The project team would like to exclude the 3-story wood frame building from the LEED project scope. The three story wood frame building is not covered by ASHRAE 90.1 - 1999, while the 6-story residence hall is covered by ASHRAE 90.1. The wood frame building is also covered by a different section of the Massachusetts Building and Energy Code than the 6-story residence hall. Therefore, we propose to make the LEED boundary include the underground parking garage but exclude the 3-story wood frame building by drawing the boundary horizontally below the wood frame and above the garage. We would propose to keep this LEED project scope of work boundary consistent through all the credits we are pursing. Please confirm that this approach is acceptable." "The project team proposes to draw a horizontal LEED boundary that will exclude a 3-story residential building from the LEED project scope, even though the buildings have a shared central plant. The residence hall qualifies as a stand-alone structure, and does not contribute towards the overall function of the parking garage or the 6-story residence hall which will be included in the project scope. Therefore, the LEED boundary may exclude the 3-story residential building from the project scope. The central plant for the project is shared between the 6-story residence hall and the 3-story residential building. For EAc1, the central plant should be modeled with identical efficiencies to those required by ASHRAE 90.1-1999, but the plant capacities (including chiller, boiler and cooling tower capacities, and circulation loop flow) should be scaled to represent the portion of peak thermal loads contributed by the 6-story structure. For example, if the peak chilled water loads are 200 tons for the 6-story structure and 100 tons for the 3-story structure, the capacity modeled for the 6-story structure would be two thirds multiplied by the installed chiller capacity." "None" "None" "LEED Interpretation" "5022" "2006-09-19" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1: Optimize Energy Performance" "Our project consists of a two story retail building. The building is open seven days a week from 9:00 am to 9:00 pm for business. We are requesting clarification regarding the modeling of lighting power density for the Proposed Design Case. In an effort to limit lighting energy usage, the project has developed two completely separate ambient lighting systems, which will NEVER operate simultaneously. A Building Automation System will be used to control the lighting systems, and to ensure that these systems do NOT ever operate in combination with one another. - System 1 consists of the general illumination (ambient lighting) having an overall LPD of 0.53 watts/sf, operational during business hours. - System 2 consists of the emergency/cleaning lighting system having an overall LPD of 0.9 watts/sf (using the ASHRAE 90.1-2004 Building Area Method). This system is a completely separate bank of lighting fixtures, which will only operate during the night for a few hours for housekeeping and maintenance, and during emergencies to provide code required egress lighting. Since the dual lighting systems have been designed for the purpose of limiting energy usage, and since these systems will never operate at the same time, we believe it would be unfair to require the project to model the cumulative lighting power density for the two systems for the ""Proposed Lighting Power Density"". Instead, we propose to model the lighting power density for the proposed case as two independent interior lighting systems for the building. The lighting power density for each system will then be compared to the base case ASHRAE 90.1-2004 building having a LPD of 1.5 watts/sf, based on the Building Area Method. For example, during store hours, the regulated lighting power would be modeled as 0.53 W/sf versus 1.5 W/sf allowed, and during cleaning hours the regulated lighting power would be modeled as 0.90 W/sf versus 1.5 W/sf allowed. We believe this modeling strategy meets the intent of the LEED v2.1 EAc1 credit by encouraging energy efficient design and controls, and by limiting total building energy consumption and costs." "The proposed modeling strategy does not comply with ASHRAE 90.1-2004. Per ASHRAE 90.1-2004, Section 9; ""Exception to 9.1.3: If two or more independently operating lighting systems in a space are capable of being controlled to prevent simultaneous user operation, the installed interior lighting power shall be based solely on the lighting system with the highest wattage."" Therefore, the proposed design must be modeled using 0.9 W/sf, for the purpose of the Energy Cost Budget calculation." "None" "None" "LEED Interpretation" "5025" "2007-01-27" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a 41,000 sqft museum building with exhibit, studio, classroom, retail, office space, and an auditorium. Because of the tight humidity control, the museum requires a constant volume air handling system for the museum spaces in the building. The constant volume system designed is permissible under the ASHRAE 90.1-1999 Chapter 6 prescriptive path. Specifically, two critical requirements of the prescriptive path are satisfied by the design: - The design\'s fan power limits are within those prescribed in section 6.3.3.1 for constant volume systems. - Reheating of the supply air is allowed per exception 6.3.2.3, as this is a museum building with a specific dehumidification system. According to the ECB method, systems with water cooled condensers and fossil fuel heating that serve multi-zone non-residential spaces shall be compared to ""System 2."" System 2 is a VAV system with chilled water and a fossil fuel boiler. Because the space-use dictates a constant volume system, and given that the proposed system is allowable per the Chapter 6 prescriptive path, we are asking the USGBC to allow us to compare the constant volume systems of the proposed design to constant volume systems in the budget building." "(Revised 2/7/07) The project is requesting a waiver from the Energy Cost Budget requirements of comparing their proposed system type to a variable volume system. Yes, the project team may model the budget building as constant volume. The project has met the requirements of table 11.4.3A note 4. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5027" "2007-01-08" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "For our project, a high rise condominium tower, we are considering providing at move-in, full coverage, insulated, automated blinds on the interior of the building as part of the energy use reduction design strategy. These blinds will be built-in, non-optional, and fully automated with a manual override to allow occupants to override the automatic settings. The alternative would normally be owner provided blinds with a wide range of characteristics, but not likely to include the heavy, insulated blinds envisioned by this energy measure. We are considering sizing the design cooling and heating so that comfort can be maintained most effectively by using the blinds. Cooling reduction will probably include some venting between the fenestration and the interior blinds so that heat that enters the glazing does not stay in the space. Can we take credit for automatic shading by using the DOE2.2 shading inputs so the energy impacts are integrated with the rest of the model? ASHRAE 90.1-2004 Appendix G indicates that manual shades and blinds not be modeled in the baseline or the design. Automatic blinds or shades can be modeled for the design, and the baseline description does not say if these are to be modeled or not. For this energy measure, variations in model schedules between the design and baseline, with clearly stated assumptions and documentation, would be the appropriate way to model the difference in the operation of blinds between the design and baseline. Other inputs would account for differences in the design blinds and typical owner blinds including R-value, and shading coefficient. Please clarify whether we can capture the efficiency benefits of this strategy within our EAc1 model, and if so, the modeling requirements per the questions above and any other factors that might apply." "The project team is seeking clarification regarding how to document the savings achieved from automated shading. ASHRAE 90.1-2004 Appendix G does allow credit in the Proposed Building model for automated shading devices, including automated blinds. No manual or automated window shading devices should be modeled in the Baseline Building model. If the energy software does not have the capability to model automated shading devices, the assumptions used for defining automated shading schedules should be clearly documented. Also, if the automated shading devices include a manual override for user control, the assumptions regarding percentage use of the automated controls should be clearly stated. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5037" "2008-06-20" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "We are requesting clarification regarding what percentage of a building must be open 24 hours for the building to be considered a 24-hour facility. ASHRAE 90.1-2004, Section 6.5.6.2 requires condenser heat recovery for preheating service hot water for facilities operating twenty-four hours per day, when the total installed heat rejection capacity of the water-cooled systems servicing the building exceed 6,000,000 Btuh, and the design service water heating load exceeds 1,000,000 Btu/h. Our project is a large retail complex which most likely exceeds the total installed heat rejection and service water heating loads listed. However, only 17% of the complex (a large arcade facility) is open 24 hours per day. The rest of the complex will be closed for a portion of each day. We believe we are exempted from the heat recovery requirement since the domestic water heating loads are mostly coming from the areas of the building that are not open 24 hours, and since only a fraction of the complex is open 24 hours per day. We would like confirmation that our interpretation is correct." "The applicant is asking to confirm their interpretation of a specific ASHRAE 90.1-2004 requirement. Based on the description provided, if the project is served by a single system, it should be considered as a 24 hour facility. If the system used for the conditioning of only the 17% of the complex (open as a 24 hour facility) does not meet the heat rejection or service water heating requirement, it would be exempt from the requirements of ASHRAE 90.1-2004, Section 6.5.6.2. Table G3.1 section 11 of ASHRAE 90.1-2004 describes the modeling requirements for service water heating systems including those covered by ASHRAE 90.1-2004, Section 6.5.6.2." "None" "None" "LEED Interpretation" "5038" "2007-02-07" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "We are requesting clarification regarding what percentage of a building must be open 24 hours for the building to be considered a 24-hour facility. ASHRAE 90.1-2004, Section 6.5.6.2 requires condenser heat recovery for preheating service hot water for facilities operating twenty-four hours per day, when the total installed heat rejection capacity of the water-cooled systems servicing the building exceed 6,000,000 Btuh, and the design service water heating load exceeds 1,000,000 Btu/h. Our project is a large retail complex which most likely exceeds the total installed heat rejection and service water heating loads listed. However, only 17% of the complex (a large arcade facility) is open 24 hours per day. The rest of the complex will be closed for a portion of each day. We believe we are exempted from the heat recovery requirement since the domestic water heating loads are mostly coming from the areas of the building that are not open 24 hours, and since only a fraction of the complex is open 24 hours per day. We would like confirmation that our interpretation is correct." "The applicant is asking to confirm their interpretation of a specific ASHRAE 90.1-2004 requirement. If the capacity that serves the 24 hour facility (described as 17% of the project) is below the ASHRAE defined limits for installed heat rejection capacity and service hot water heating loads, then the project does not need to follow the requirements of ASHRAE 90.1-2004 Section 6.5.6.2. If the capacity is greater than the defined limits, then the project must follow the requirements." "None" "None" "LEED Interpretation" "5039" "2007-03-15" "New Construction" "EAc1: Optimize Energy Performance" "The intent of this credit is to ""Achieve increasing levels of energy performance above the baseline in the prerequisite standard to reduce environmental and economic impacts associated with excessive energy use."" The requirements of Option 1 of this credit are as follows: - Demonstrate a percentage improvement in the proposed building performance rating compared to the baseline building performance rating per ASHRAE/IESNA Standard 90.1-2004 (without amendments) by a whole building project simulation using the Building Performance Rating Method in Appendix G of the Standard. Table G3.1, number 5.a. in Appendix G of the Standard concerns orientation. The baseline requirement is as follows: - The baseline building performance shall be generated by simulating the building with its actual orientation and again after rotating the entire building 90, 180, 270 degrees, then averaging the results. The building shall be modeled so that it does not shade itself. The exception that we would like to take is as follows: - The intent of the baseline requirement is to encourage thoughtful orientation of a building that results in energy savings. The Project is an exception to this approach. The orientation of the ballpark is not negotiable because of sun direction and the function of the ballpark. The shape of the facility and orientation of ancillary spaces, is fixed due to the orientation and shape of the playing field. The ballpark\'s orientation is not site related. The orientation would generally be the same whether the ballpark was on a constrictive site or constructed on a site where orientation could be optimized for energy savings. - We would like to model the baseline building performance and the proposed building performance with the same orientation-the project\'s actual orientation. We ask that this exception is made for the project." "As stated in Appendix G, section G4.1, the baseline building model must be rotated in the four directions. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5040" "2007-05-13" "New Construction" "EAc1: Optimize Energy Performance" "The intent of this credit is to ""Achieve increasing levels of energy performance above the baseline in the prerequisite standard to reduce environmental and economic impacts associated with excessive energy use."" The requirements of Option 1 of this credit are as follows: - Demonstrate a percentage improvement in the proposed building performance rating compared to the baseline building performance rating per ASHRAE/IESNA Standard 90.1-2004 (without amendments) by a whole building project simulation using the Building Performance Rating Method in Appendix G of the Standard. Table G3.1, number 5.c. in Appendix G of the Standard concerns vertical fenestration. The baseline requirement is as follows: - Vertical fenestration areas for new buildings and additions shall equal that in the proposed design or 40% of the gross above-grade wall area, whichever is smaller, and shall be distributed uniformly in horizontal bands across the four orientations. The exception that we would like to take is as follows: - The intent of the baseline requirement is to encourage thoughtful fenestration orientation and glazing percentage of a building that results in energy savings. The Project is an exception to this approach. - The facility exists for the purpose of sports viewing. The field-side glazing exists in order for the facility to function as intended. - The exterior walls of concessions, restrooms, and other ancillary spaces typically do not have glazing. Concessions and restrooms are typically semi-heated only. Modeling the baseline with glazing distributed over the concessions and restrooms doesn\'t seem to meet the intent of the Standard. - We would like to model the baseline building performance and the proposed building performance with the same vertical fenestration-the actual building fenestration. We ask that this exception is made for the project." "The baseline and the proposed design can be modeled with the windows distributed around the building as in the proposed design. The baseline cannot have more than 40% window area as a percentage of total wall area. As posted on the USGBC website, project teams can use addenda in the most recent Supplement to the ASHRAE standards (see http://www.usgbc.org/ShowFile.aspx?DocumentID=2664). Addendum A documents this change. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5041" "2007-03-15" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The intent of this credit is to ""Achieve increasing levels of energy performance above the baseline in the prerequisite standard to reduce environmental and economic impacts associated with excessive energy use."" The requirements of Option 1 of this credit are as follows: - Demonstrate a percentage improvement in the proposed building performance rating compared to the baseline building performance rating per ASHRAE/IESNA Standard 90.1-2004 (without amendments) by a whole building project simulation using the Building Performance Rating Method in Appendix G of the Standard. Per Appendix G of the Standard, table G3.1.3.7: The baseline requirement is as follows: - Since the conditioned floor area is greater than 240,000 square feet, the baseline building chiller plant shall consist of 2 centrifugal chillers minimum with chillers added so that no chiller is larger than 800 tons, all sized equally. The exception that we would like to take is as follows: - We recognize the baseline requirement for centrifugal chillers on this size of project. Our experience with a number of recent projects similar in size and use to this project indicates that air cooled chillers are more cost effective over the long term investment. When analyzed as a total system in comparison to water cooled chilling systems, air cooled chillers offer several cost advantages. Advantages include less equipment to purchase, less equipment to install, smaller space use requirements, less maintenance, less refrigerant, and less water use. - We are requesting that air cooled chillers are allowed to be used when modeling the baseline building performance for this project." "ASHRAE 90.1-2004, Appendix G, establishes the baseline HVAC system in Table G3.1.1.A. For this size facility, Appendix G requires that the baseline have a chilled water system with water-cooled chillers. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5043" "2007-03-23" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "This Credit Interpretation Request is in reference to a 92,000 square foot office building and research laboratory that includes a 5000 square foot data center. To obtain credits for Optimized Energy Performance, we plan to estimate the energy consumed using Option 1-Whole Building Energy Simulation as outlined in ASHRAE 90.1, Appendix G. The LEED modeling protocol sets the process load as 25% of the total building energy load. Credit Interpretation for Energy and Atmosphere EAc11 dated 11/3/2006, ruling #5 \'addresses setting the process load at 25% of total energy by default, unless it is a process dominated building\'. The portion of non-regulated energy consumed by the data center equipment and the research laboratory will exceed 50% of the total building load and will dominate the total building energy use. The large non-regulated process load of the data center and research lab will unfairly minimize the percentage of total energy savings applied to the regulated loads. In order to fairly evaluate energy savings of the enhanced building and systems, as well as utilizing photovoltaic arrays, we plan to exclude the energy consumed by the equipment associated with the data center and research laboratory from the energy simulation calculations. It is noted that with the process equipment in the labs and the data center equipment loads, this percentage of energy derived from the PV array will be very small. Is this the proper approach, or should we use the default process load of 25% of the total building load, or the actual loads for these systems?" "The project is requesting clarification regarding modeling procedure for buildings where process energy constitutes a large portion of the total building loads. According to Appendix G, Table G3.1.1, ""all end-use load components within and associated with the building shall be modeled."" The ""default"" process energy of 25% defines the minimum percentage of process energy that should be modeled for a typical building. However, buildings that exceed this percentage should model the process energy as designed in accordance with the Appendix G requirements. For buildings that are lower than this percentage, the LEED submittal must include supporting documentation substantiating that process energy inputs are appropriate. This process energy may not be removed from the model during post-processing, and must be included when calculating the Baseline Performance, Proposed Performance, and Percentage Improvement. For buildings where process energy constitutes a large portion of the total load, the Baseline HVAC assumptions listed in Appendix G allow for substantial energy improvements for a well-designed HVAC system. According to Exception to G3.1.1, System 3 or 4 (a packaged single zone system) shall be modeled for any space that has occupancy or process loads that vary significantly from the rest of the building, including peak thermal loads that differ by at least 10 Btu/h-ft^2. Therefore, for a building with a large data center, the HVAC energy savings potential relative to the Baseline design is far greater than for a similar office building without a large data center. As a result, the percentage energy savings for a good design may be comparable between the two cases even though the process energy costs as a percentage of total energy are significantly different. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5057" "2007-07-02" "New Construction" "EAc1: Optimize Energy Performance" "The Yale Social Sciences Building will be a 72,000 ft2 addition to the Yale University campus in New Haven, Connecticut. The design is currently in the CD phase, and the building includes classrooms, study areas, and faculty offices. Like the rest of Yale University\'s central campus, this building will be connected to the Yale Central Plant for supply of chilled water, steam, and electricity. The Yale Central Plant is a highly efficient generator of steam, chilled water, and electricity. By making use of natural gas to generate steam in high efficiency boilers, the plant can then choose to produce variable amounts of electricity and chilled water from steam driven turbines and chillers, in addition to natural gas turbines. Though the plant itself is highly efficient, the pricing of its product is inclusive of an extensive supply network and union labor force. The central plant is up-to-date with LEED compliant refrigerants, NOx, SOx & particulate filtration, and is part of the Yale initiative to reduce campus greenhouse gas emissions 10% below 1990 levels by 2020. In comparison to the extensive use of trash-to-energy in CT, we feel that this is an efficient source of local clean energy for the building. This credit interpretation request is in regards to energy modeling of the chilled water sourced from the Central Plant for cooling as compared to the baseline building. Intended to discourage the use of old, inefficient central chilled-water plants, ASHRAE 90.1-2004, Appendix G requires that the Baseline Building be simulated with a DX rooftop system. The annual energy costs for the Baseline Building are then compared to the annual energy costs of the Proposed Building, which uses chilled water from a central campus plant, to determine the number of credits attainable under EAc1.1-1.10. This comparison is problematic, because it penalizes any building without on-site chilled water generation, regardless of the efficiency of the central plant. An energy consumption comparison between the Baseline Building and the Proposed Building will then be inaccurate, because chilled water demand does not incorporate any coefficients of performance (COPs) for the chilled water generation. Therefore, following the ASHRAE methodology, it will be difficult to meet the Minimum Energy Performance prerequisite of LEED-NC 2.2, much less earn any EA-1 points. Exacerbating the problem, the highly-efficient central plant reuses energy at every step of the production process, making it difficult to price each utility completely accurately. Thus, the ASHRAE 90.1-2004, Appendix G model is not a comparison of the Baseline and Proposed Building\'s energy efficiency, but instead is a model of the discrepancies between the prices of electricity and chilled water. One method of creating a useful comparison between the Baseline and Proposed Buildings would be to ""normalize"" the cost of electricity relative to chilled water. As the USGBC has previously established that utility costs must be inclusive of all labor and delivery costs and cannot be modified (9/19/2006), we propose the following alternate method for modeling the Baseline Building. We propose that in the case of a new building being serviced by an existing campus utility plant, the ASHRAE 90.1-2004 Baseline Building use chilled water from the central plant. Utilized under previous versions of ASHRAE 90.1 and currently under ASHRAE 90.1 - 2004 for all but the method stipulated in Appendix G, the proposed methodology provides a more accurate depiction of energy savings achieved in the Proposed Building. It would provide a consistent comparison of cost of energy to the owner and more realistically equate energy savings with LEED points. Please confirm that the USGBC will find it acceptable to use this methodology when dealing with new buildings on the Yale campus that connect to the campus central plant." "The project is a new building connected to a campus combined heating, cooling and power (CHP) central plant. Based on the size of the project and type, the baseline system for this project is System 3 - PSZ-AC. The project is requesting a waiver for the Baseline system selection requirement to be able to account for the efficiency of the central plant. The USGBC has published a white paper titled - ""CHP Calculation Methodology for LEED-NC v2.2 EA Credit 1"" available on the USGBC website. Based on the project narrative and the CHP calculation methodology, this project will be considered under the CHP Table 1 ""Summary of CHP Cases"" as a Case #3 classification. To achieve any credit under EAc1, all applicable requirements of ASHRAE 90.1-2004 Appendix G and any applicable items under the referenced white paper need to be followed without exception. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5060" "2007-07-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "ASHRAE 90.1 sets specific requirements for the building envelope, including meeting all requirements of Section 5.4. Air Leakage, Section 5.4.3, requires sealing, caulking, gaskets and weather stripping of the building envelop to minimize air leakage. For the Barkesdale Dormitory, additional methods were used to minimize air infiltration. Additional barriers, taping, and low leakage panels per ASTM E283-84 (0.06 cfm per square foot of fixed wall at 63.3 mph wind and 1.92 iwg.) were used. Additionally, the building was pressurized to prevent infiltration. A baseline building model is neutral with average construction. With the value added benefit of additional barriers, taping and low leakage panels and pressurization, the Barkesdale Dormitory can be considered a ""tight-pressurized construction"". These differences could effect the energy calculations. Is this a logical conclusion?" "This CIR seeks to use reduced infiltration rates from a superior building envelope as a variable in the energy cost budget calculation for optimizing energy efficiency. The ASHRAE modeling protocol does not allow the infiltration rate to be changed between the budget and the design case. The CIR ruling of 3/11/2003 for EAc1.2 provides some guidelines on how a case might be made for advanced air sealing. The methodology proposed for this project does not address all the issues raised in that ruling and would be insufficient to grant an exception to the modeling protocol. Applicable Internationally. " "3300" "None" "X" "LEED Interpretation" "5085" "2008-08-26" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "We are proposing a 180,000 sf office building in Austin, TX that is tying into an existing Austin Energy District Cooling loop. This chiller plant is part of a larger campus that is being changed over from a manufacturing and office campus to a multi-use development. The was designed to achieve an Austin Energy Green Building (AEGB)commercial 2-star rating, but the goal was changed to LEED-CS since the AEGB program does not include provisions for Core and Shell projects. Upon switching over to LEED-CS, it was discovered that the energy efficiency minimum had changed. In modeling the building to determine if we could meet the revised minimum energy efficiency, we found that the baseline we are to compare to per ASHRAE 90.1-2004 Appendix G is the same as our proposed building: district cooling. As a result, the inherent efficiencies found in the district cooling system are lost, unless we construct our own chiller as part of this project. Given that lighting, process, and plug loads must also be equivalent in the baseline and proposed cases, it is very difficult to see reasonable efficiency percentage changes, even with the most efficient envelope and heating systems. Their overall percentage effect on the total energy use is too small to make the 14% reasonably achievable as a minimum efficiency. Based on discussions with similar project teams in the area, our situation is not unique. What we are requesting is either that: 1. The baseline is revised such that the use of an existing district chilling plant is not penalized. We feel that the intent of the current baseline is to encourage sustainable energy use on a holistic level, not to encourage individual projects to build their own chiller plants. 2. The minimum percentage be revised for such Core & Shell scenarios where areas in which there are opportunities for improvement in energy efficiency are minimal." "The applicant is requesting clarification on the LEED-CS v 2.0 requirements for energy analysis. For the proposed design using purchased chilled water, the design must use the actual utility rate for the purchased chilled water. The baseline model must use chillers designed to meet all requirements of sections G3.1.3.7 and related sections of ASHRAE 90.1-2004 Appendix G. The inherent efficiencies in the central plant are accounted for in the cost of the chilled water versus the cost of electricity to generate and circulate the chilled water on site. Please also see the document titled, ""District Thermal Energy Treatment"" on USGBC\'s website (http://www.usgbc.org/ShowFile.aspx?DocumentID=4176). This may also be used as an acceptable modeling compliance path. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5088" "2007-11-27" "New Construction" "EAc1: Optimize Energy Performance" "Our project is located in Las Vegas and consists of a combination of office spaces and maintenance bays for earth-moving equipment. The owner is a large agency that sells, rents and repairs such equipment; these repairs are done both inside and outside the building envelope. The maintenance bays are occupied by mechanics and will be conditioned with evaporative coolers and gas furnace heat, the system supplies 100% outside air. This cooling system provides conditioning of the spaces but is not able to meet all peak loads for a climate such as Las Vegas even when these spaces are modeled with higher setpoint at 80 degrees. In reality, if the maintenance bays go above the temperature setpoints, the mechanics will continue work in the warmer conditions or take a break. This is not difficult for maintenance bays, where some of the work will also done outdoors with no conditioning at all. The owner does not want to fully condition the maintenance bays with the intention of achieving high levels of energy efficiency. We propose the following modeling approach for EA Credit 1. -Baseline model will have a mechanical system based on Table G3.1.1A of Appendix G with 80 degree temperature setpoint for the maintenance bays. -Proposed Design model will have the system as designed in the building that provides partial conditioning with the same 80 degree temperature setpoint. We will not model additional compressor cooling for hours where the system is not able to meet loads. This approach will result in exceeding the difference in the unmet load hours beyond 50 as required by Appendix G. However, this is a conscious decision by the owner who wants to maximize energy efficiency by providing limited conditioning through evaporative cooling for the maintenance bays, and allow the temperatures to float higher during peak conditions. We feel that this approach appropriately captures the intent of the design, and gives credit to the energy efficiency measures being taken. It also provides a way for demonstrating the value of an energy efficient approach to the community in Las Vegas where compressor cooling is increasingly used, often indiscriminately; this is a desert climate and a different approach to comfort and conditioning is possible. Is this approach acceptable? If not, can you advise us on an alternative approach that addresses the desire of the owner to demonstrate high levels of energy efficiency for using such a system?" "It is not acceptable to allow spaces to exceed the unmet load hour requirements of the ASHRAE 90.1-2004 Appendix G methodology. This is a similar situation to naturally ventilated spaces, which are required to include cooling systems to meet space loads in the proposed case even if the actual building will contain no cooling. Building owners may always choose to turn off HVAC systems, or not have them installed at all to conserve energy, but the ASHRAE modeling protocol assumes that cooling systems will be installed and run with sufficient capacity to meet space loads. The applicant may use a set-point of 80 degrees Fahrenheit for the maintenance bays, but cooling system capacity must be increased until the requirements of ASHRAE 90.1-2004 section G3.1.2.2 are met. The project may still receive credit for using an efficient cooling system as compared to the ASHRAE baseline cooling system. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5102" "2008-02-26" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project includes two indoor swimming pools - one lap pool and one recreational pool. We plan to claim energy savings for the pools and natatorium. ASHRAE 90.1 will be used as the baseline for those elements that are covered by the standard; pool heating boiler performance, space ventilation fans, and lighting. For the performance of other pool equipment not addressed by the standard, specifically pool circulating pumps, the pool filtration systems, and the natatorium humidification control, we are proposing the baseline to be a recently completed pool that is owned and operated by the same entity as this project. We will quantify the baseline through field measurements and interviews as appropriate. Baseline pool circulation rates will be determined by the local health code and heating energy and evaporation rates will be calculated using the Energy Smart Pools software (see http://www.rlmartin.com/rspec/). Adjustments will be made to the baseline to account for each pool\'s temperature and activity rate impacts on evaporation in order to calculate natatorium dehumidification requirements. Pool and natatorium energy efficiency measures that we plan to carefully consider include optimum selection of pool circulating pumps for maximum efficiency, minimizing the total pressure drop through the pool circulation systems, variable speed circulation pumps, dehumidification (either mechanical or with outside air) with heat recovery, and a solar make up air preheating system. The savings for the potential pool and natatorium measures will be calculated from the baseline described above. Is this an acceptable methodology to establish the baseline and energy savings for the non-regulated loads in the pools and natatorium?" "Per the LEED NC 2.2 Reference Guide, page 183, ""project teams may follow the Exceptional Calculation Method (ASHRAE Std 90.1- G2.5) to document measures that reduce process loads. If credit is taken for process loads, the calculation must include reasonable assumptions for the baseline and proposed case."" ASHRAE 90.1-2004, G2.5 further states ""Applications for approval of an exceptional method shall include documentation of the calculations performed and theoretical and/or empirical information supporting the accuracy of the method."" In the above request, there isn\'t sufficient information supporting the accuracy of the method or describing how to document calculations performed. Information from only one recently built pool does not constitute ""empirical"" data. In this case, the USGBC certification reviewer serves as the ""rating authority"" described by ASHRAE Std 90.1- G2.5 and will make rulings on a case by case basis. The pool system savings fall under the process load category and thus the Exceptional Calculation Method should be used to take credit for energy savings, per ASHRAE 90.1 G2.5. The burden of proof regarding what constitutes ""information supporting the accuracy of the method"" rests with the project team. As far as energy savings from the natatorium (space) measures, this should be addressed within the confines of the Performance Rating Method of ASHRAE 90.1-2004, per the exception made under G3.1.1(b). Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5113" "2008-03-04" "New Construction" "EAc1: Optimize Energy Performance" "The design team is seeking clarification on credit EAc1- Optimize Energy Performance, specifically in regard to the use of the Core Performance Guide. The project in question is a Multi Axis Simulation Table (MAST) facility for Caterpillar Corporation. The facilities function is to conduct accelerated durability tests on industrial construction equipment through simulated usage on a large table that imposes dynamic forces on construction equipment with hydraulic rams. As such these facilities have an energy use profile significantly weighted towards process energy use. This energy profile will likely result in an inability for the project to achieve the 14% energy savings over ASHRAE 90.1-2004 that is now required by LEED NC v 2.2. Because of this, the project would like to pursue the Core Performance Guide compliance path. Prior to submission we would like to be certain that our project is applicable to the Core Performance Guide option. Can the USGBC please define the terms ""Laboratory Building"", ""Warehouse Building"" and ""Health Care Building"" or otherwise offer criteria by which our client can determine how the USGBC will view our project?" "The project team has requested clarification on whether OPTION 3 — PRESCRIPTIVE COMPLIANCE PATH: Advanced Buildings™ Core Performance™ Guide (2-5 Points) would be applicable to their project (a Multi Axis Simulation Table facility). It is the responsibility of the project team to properly define its building type and make the case accordingly in their submittal." "None" "None" "X" "LEED Interpretation" "5118" "2008-04-23" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project has developed a strategy for energy savings using diesel power generators on site and considering fossil fuel rates in lieu of utility demand rates during peak time. EnergyPlus results for the project have confirmed that savings with this particular strategy correspond to 14% of the baseline energy cost. Energy consumption rates are regulated by the local utility. - Peak Time: 107.56 USD/MWh | Off-Peak Time: 67.33 USD/MWh During off-peak time, the energy consumption rate will be considered in both baseline and proposed design calculations. During peak time, the energy consumption rate will be considered only in baseline. In the proposed design, power generators will operate on site during this period and the local utility will not be the supplier; consequently, the energy consumption rate will consider only the fossil fuel to operate the power generators. - Fossil Fuel: 405.50 USD/MWh Demand rates are regulated by the local utility. - Peak Time: 16.93 USD/kW | Off-peak Time: 4.15 USD/kW During off-peak time, the demand rate will be considered in both baseline and proposed design calculations. During peak time, the demand rate will be considered only in baseline. In the proposed design, power generators will operate on site during this period and the local utility will not be the supplier; consequently, the demand is free of charge. Running Energy Plus for a single month, the project has had the following results. - Energy Consumption Peak Time: 65 MWh | Off-Peak Time: 610 MWh - Demand Peak Time: 1,918 kW | Off-Peak Time: 3,196 kW Considering only this month as an example of energy savings (the actual simulation takes into account the whole year), calculations should go as follows. Baseline: 65 MWh x USD 107.56 + 610 MWh x USD 67.33 + 1,918 kW x USD 16.93 + 3,196 kW x USD 4.15 = USD 93,797.84 Proposed: 65 MWh x USD 405.50 + 610 MWh x US$ 67.33 + 1,918 kW x USD 0.00 + 3,196 kW x US$ 4.15 = USD 80,692.20 (14% less cost than that from the baseline) This CIR is to confirm that the approach described above is acceptable for achieving points in EA credit 1, considering power generators on site and reducing billing rates." "The applicant is requesting clarification regarding whether peak shaving of purchased electric demand accomplished through on-site diesel generators may be used to demonstrate energy cost savings for EAc1. These cost savings may only be reflected if the generators are modeled using the methodology defined in the CHP Calculation Methodology for LEED-NC v2.2 EA Credit 1 (https://www.usgbc.org/ShowFile.aspx?DocumentID=1354) and the generation system meets all of the CHP System Qualifications criteria listed in this document. Most diesel generators will not meet the requirements spelled out in the CHP calculation methodology. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "5119" "2008-04-25" "New Construction, Core and Shell, Schools - New Construction" "EAc1: Optimize Energy Performance" "Our project is a new elementary school ( one-story, 85,940sf ), based on an existing prototype design layout that has been implemented for the last ten years throughout the City of Virginia Beach. This design is similar to Hermitage ES, which previously received certification and is used as an example in LEED for Schools. In keeping with other LEED philosophies, the City elected to re-develop the existing site for this project. Our project includes an existing school building on this pre-developed site. The existing school building and site will remain in operation, until the new building is completed. Since this project includes constructing a new school on an existing site ( with existing building and parking areas to remain in operation ), the project lacks the available land necessary for exploring mechanical systems to optimize energy savings ( such as geo-thermal ). As a result, the building design is struggling to meet the mandatory 2 Credits for EA C1. The Design Team is attempting to achieve the 2 Credits through the available Option: Prescriptive Compliance Path - Advanced Core Performance Guide. Under ""Building Configuration"" part of this guideline, there is a requirement to analyze three alternate building configurations to determine the most energy efficient configuration. While the design team did not develop three different design configuration concepts ( different footprint layouts ), an energy analysis of the proposed prototype building design layout was performed from all four orientations. The following is a breakdown of the cost comparison findings: 0 Degree Rotation: $ 63,432.00 90 Degree Rotation: $ 63,247.00 180 Degree Rotation: $ 63,300.00 270 Degree Rotation: $ 63,316.00 The results suggest that the annual energy cost difference from low to high between all four orientations is neglible (less than $200 a year). Therefore, the new school building prototype design layout, location and orientation is an energy efficient layout given that this is an existing site, and therefore complies with the essence of USGBC - LEED\'s ""general intent"" - to develop a building design layout with consideration to energy use and existing site conditions. Please confirm that our approach is acceptable to qualify for the mandatory 2 credits for EA C1." "The project team is asking for confirmation of their approach to one specific requirement of the Advanced Buildings Core Performance Guide. The project team\'s approach of modeling the building in four different orientations because of site restrictions does comply with the Building Configuration requirement of the Advanced Buildings Core Performance Guide. Please note that all other necessary requirements of the referenced standard must be followed in order to earn points for this compliance path. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "5121" "2008-05-27" "New Construction" "EAc1: Optimize Energy Performance" "Intent: To properly calculate the energy points available in EA credit 1 Option 1 for connection to an innovative district cooling system in lieu of constructing an independent building cooling plant system. Background: The project designed and connected to an innovative district cooling system in lieu of building an independent cooling plant system for the new office. District Cooling has also proven to be a major contributor to Greenhouse Gas reduction in many cases. It displaces peak electric power demand with district cooling and storage using ice or chilled water. This benefits the local power grid by reducing peak power demand and alleviating power congestion due to power transmission limitations in cities. So district cooling not only helps cool cities, it helps alleviate the challenges posed by high electric consumption. It is considered that the project may account for the environmental benefit of connection to an efficient central system through points in EAc1 because of significant energy cost saving. While the highly prescriptive modeling outlined in ASHRAE 90.1 and the LEED template does not clearly identify methodology for proposed modeling that would be appropriate to recognize the environmental benefits of tying into this central system rather than utilizing building-specific refrigerant systems. Proposal: We propose to follow the methods specified in credit EAc1 with the following clarification: For modeling cooling energy use, two steps are proposed for the energy model implementation. Step 1 (Building stand-alone scenario): Perform an initial model run on the project building to determine the number of EAc1 point earned without the effect of the district cooling system, i.e. by modeling only purchased chilled water for both baseline and proposed model with actual energy source cost. The achievable points will be depended on the cost saving according to EAc1 requirement. Step 2 (Aggregate building/District Energy Source scenario): Perform a second model run that incorporates the effects of the district cooling system. For the baseline model rats are applied to the code-compliant cooling plant as instructed in Appendix G. Chiller efficiency with energy losses will be used in the proposed model. The achievable points will be depended on the cost saving according to EAc1 requirement. The total number of EAc1 points achievable will be points gained in Step 1 and a maximum 4 points in Step 2. Please confirm that this is an appropriate method for modeling the proposed model condition and comparing energy impacts." "The applicant is requesting a methodology for documenting improved energy efficiency performance under EAc1 for linking buildings to an efficient District Cooling Plant. The USGBC has just released a document entitled ""Required Treatment of District Thermal Energy in LEED-NC v2.2"" (https://www.usgbc.org/ShowFile.aspx?DocumentID=4176)."" This modeling methodology will be required for all projects registered on or after the date it was posted, but all LEED-NCv2.2 projects registered before that date are also allowed to follow this guidance to take credit for District Heating and Cooling. Please apply the methodology outlined in this document in order to appropriately credit the District Cooling system performance to this project. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "5135" "2008-08-02" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Saint Ann Court is a LEED registered 26-story high rise office project being developed by Dallas-based Harwood International. Saint Ann Court is located in the Uptown area of Dallas, Texas, adjacent to Dallas\' Central Business District. The Saint Ann Court project team is currently expecting to acquire 38 LEED points on the Core and Shell v2.0 Registered Project Checklist. At the completion of design, the building was in full compliance with LEED Standards and received a building permit prior to June 26, 2007. Due to escalating construction costs and negotiations with the general contractor, the project was not registered with the USGBC after June 26th. The energy modeling for credit EAc1 Optimized Energy Performance was completed last week and the building is currently only 8% more efficient than the baseline design. The first thought was to change the glass since 65% of the building is glass. This solution may no longer be an option, as the Owner has also made move-in date commitments to tenants that do not allow time for losing our production slot at the glass manufacturer should a change in glass be necessary. The mechanical/electrical design engineer is in the process or reviewing efficiency of the HVAC systems to see if additional reduction in energy consumption is possible. This high profile urban project attempting a Gold level certification is in jeopardy of not achieving any certification level with the additional energy performance requirements becoming effective after design and permitting of the project was completed. We believe we can reach the 10.5% in Eac1 with additional insulation installed behind the glass and precast concrete spandrel panels and modifications to the HVAC equipment. We are, however, respectfully requested a variance for this project to continue attempting Gold level certification under the pre June 26, 2007 date allowing 1 credit minimum to be met under Eac1. Harwood International has always constructed developments under strict guidelines to create high performance green buildings. Harwood has made LEED certification a standard requirement in the Harwood Master PD as well as other PD\'s within its Uptown holdings. At completion, the Harwood master planned development will encompasses 8 million square feet of city approved, LEED Certified square footage in 20 development projects. Among the five operating buildings located in Uptown Dallas that Harwood has developed, many have received awards. The Rolex building recently won the Dallas Toby ""Office Building of the Year"" Award, and the Centex building received the EPA Energy Star award as well as it being rated the most energy efficient office building in the U.S. Harwood International has never taken tax dollars from the city, and continues to beautify the area by planting their own trees and incorporating 6.5 acres of parks on private property at owner\'s cost." "The project team is requesting a variance from meeting the mandatory achievement of 2 points under EAc1. Per CIR Rulings dated 11/14/2007 and 11/28/2007, and the errata for LEED-CS v2.0 on the USGBC website (http://www.usgbc.org/ShowFile.aspx?DocumentID=3334), there are other efficiency measures that can and should be pursued to meet the minimum target of 14% in energy cost savings. As the opportunity to pursue measures mentioned in the above CIRs and errata exists for this project, the request for variance is denied." "None" "None" "LEED Interpretation" "5139" "2008-08-26" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our project is being considered for re-registration from LEED-CS v2.0 to LEED-NC v2.2. The building is 65,762 GSF with 48,664 SF of total leasable space. 25,997 SF (53%) of the building has been leased, designed, and under construction. However, the remaining 22,667 SF (47%) is unleased shell space. The unleased shell space is outside of the project scope and there is no design currently underway for this to complete work in this area. In order to pursue EA Credit 1 (Optimize Energy Performance), our engineers would like guidance on how to create their energy model based on our building situation of 53%-to-47% leased vs. shell spaces. It is their intention to model the unleased shell space as if the space were ""upfit"" to the same standard as the leased portion of the building. This standard would be described in a tenant improvement guidelines provided to future tenants. Please verify this method is acceptable or provide an alternate method for energy modeling." "The applicant is requesting clarification regarding energy modeling of shell spaces that do not yet include tenant fitouts. This topic has been extensively addressed in the published erratum for LEED-CSv2.0 (http://www.usgbc.org/ShowFile.aspx?DocumentID=3334), as well as previous CIR rulings (CSv2.0 Rulings dated 05/27/2008, 04/25/2008, 04/23/2008, 04/24/2008, 02/11/2008, 11/28/2007, 12/5/2007, 11/14/2007, and 05/30/2007). For LEED-CS, tenant guidelines alone are not sufficient to verify energy efficiency measures incorporated into future leased space. The published erratum indicates that documentation should be provided including lease or sales agreements verifying that 100% of the leased square footage complies with the credit requirement, and a statement signed by the owner / developer verifying that all leases and/or sales agreements will comply with the credit requirements. For future leased spaces, the letter from the owner / developer is only required if efficiency measure improvements beyond ASHRAE 90.1-2004 are reflected in the future leased spaces (e.g. improved lighting power density, improved HVAC efficiency, etc.). Applicable Internationally." "None" "None" "X" "LEED Interpretation" "5156" "2008-10-24" "New Construction" "EAc1: Optimize Energy Performance" "Our project involves a new 817,000 square feet facility located designed for the production and storage of multiple milk-based products. The project is targeting a LEED Silver certification, which includes earning points under EAc1. The project includes two process efficiency improvement measures for which we will submit exceptional calculations for documenting savings. We would like to verify that the assumptions and supporting documentation are acceptable. High Efficiency Steam Boiler Plant The boilers installed in the facility include two (2) 82,000 PPH steam boilers, which only serve the industrial processes. They do not serve any HVAC loads Design Performance - The as-designed steam boilers have a thermal efficiency of 83%. This is based on manufacturer\'s performance data. - Each as-designed steam boiler has a stack economizer and a condensing stack economizer. Together they increase efficiency by 12%. The economizers are used to preheat boiler feed water. - In addition, rejected heat from the process water systems is used to preheat boiler cold-water make up (138 GPM) from 70 F to 110 F through a plate and frame heat exchanger. This adds an additional 2% savings to the overall thermal efficiency of the boilers. - Manufacturer\'s data and engineering calculations will be supplied to support the efficiency claims listed above. The data will include inlet and outlet flows, temperatures, pressures, and enthalpies. The overall efficiency will be calculated based on the rated boiler efficiency and the additional heat reclaim. Baseline Performance - The baseline steam boiler efficiency is assumed to be consistent with the ASHRAE 90.1-2004 minimum efficiency requirements for large boilers. From Table 6.1.8F, the combustion efficiency for a gas-fired boiler > 2.5 MBtuh is 0.80. Thermal losses of 2% are assumed from the boiler shell. Thus, the thermal efficiency of the Baseline steam boiler is assumed to be 78%. Exceptional Calculation Approach The DOE-2.2 computer program will be used to model the steam boilers based on the facility process loads, equipment thermal efficiency, and part load performance. Refrigerated Warehouse Building Design The as-designed refrigerated warehouse has a reduced footprint due to the incorporation of an automated mechanical storage and retrieval system, which reduces aisle size requirements since fork lift maneuvering is no longer required. The design team compared the two design options and determined that the floor area for the automated warehouse is ~ 25% of that determined for the typical warehouse. In addition, the as-designed warehouse operates in a lights out environment except for maintenance, which requires lights on for ~ 1% of the year. Examples of recently constructed warehouses providing similar service without automated storage will be provided to document that this is typical of new design. Design Performance - Foot print of 110,600 square feet, height of 112 feet based on construction drawings - Lighting power density of 0.8 W/ft2, lights on 0.7% of the time (lights out facility) - Building maintained at 42 F Baseline Performance - Footprint of 469,800 square feet, height of 112 feet. The footprint and height is based on vendor\'s detailed engineering calculations that compares the design, capital costs, and estimated operating costs for an automated and non-automated facility. - Lighting power density of 0.5 W/ft2 (per ASHRAE 90.1), lights on100% of the time since it is continually operated. - Building maintained at 42 F Exceptional Calculation Approach The DOE-2.2 computer program will be used to determine energy costs for a revised baseline building that includes a larger refrigerated warehouse without automation." "The project team seeks verification of the approach to account for and document process energy savings. Specifically, the project team requests verification on the design and baseline cases for two boilers intended for process use, and for a reduction in footprint and lighting availability in the design case as compared to a larger, non-automated warehouse facility. The approach used for arriving at an appropriate baseline for the steam boiler plant seems reasonable. The reduction in floor area for the proposed design (automated case); is not permissible under Table G3.1, No.1 of Baseline Building Performance in ASHRAE 90.1-2004. The baseline building must be modeled with identical conditioned floor conditions as the proposed design. It is recommended that any savings associated with the automated operation in the proposed design be documented through the use of an exceptional calculation method (Section G2.5 of ASHRAE 90.1-2004, Appendix G) that supplements the procedure required per ASHRAE 90.1-2004, Appendix G. If credit is taken for measures including but not limited to lighting power density, occupant density, equipment power density, or floor area reduction, please provide sufficient justification in the submittal." "None" "None" "LEED Interpretation" "5157" "2009-01-23" "New Construction" "EAc1: Optimize Energy Performance" "The project is the major renovation of 7 separate 3-story, Low-Rise, multi-family residential apartment buildings, totaling 137,600 SF. All buildings will maintain at least 90% of the existing building envelope and are collectively pursuing LEED NC 2.2. The project was registered on 06/27/2007 (Invoice ID: 90138627) under the applicable LEED ratings system, LEED NC 2.2. LEED NC 2.2, 2nd Edition, only recognizes ASHRAE 90.1-2004 as the acceptable baseline standard for evaluation of EA Pre-Requisite 2 and EA Credit 1. However, this standard only applies to Commercial buildings and High-Rise Residential projects. In addition, the ASHRAE 90.1 standard sites the ASHRAE 90.2 standard as the applicable standard for Low-Rise residential buildings. This project was designed in accordance with the most stringent applicable code standard for energy efficiency, ASHRAE 90.2-2007. According to a CIR ruling dated 4/19/2004, the USGBC allowed for low-rise residential projects to be evaluated under LEED NC 2.1 using the LEED Application Guide for Lodging as a guideline. The LEED Application Guide for Lodging established the use of ASHRAE 90.2 as the relevant Baseline standard for EAp2 and EAc1 instead of ASHRAE 90.1. There had been no subsequent clarification for low-rise residential projects at the time that this project registered with USGBC. As such, this project was designed and evaluated in accordance ASHRAE 90.2-2007 using the LEED NC 2.1 ruling as a guideline. Low-rise residential projects are currently being evaluated under LEED-Homes. Design for the project originally began in early 2007 and construction began on September 1, 2008. At the time of registration, LEED Homes Pilot only allowed for new construction projects, and at the time of design it was not evident how renovation projects, and in particular, multi-family renovation projects, would be evaluated under this rating system. The project, therefore, proceeded with its only available USGBC option and registered under LEED-NC 2.2. We are seeking clarification that ASHRAE 90.2-2007 is the applicable standard for its evaluation of EAp2 and EAc1 for a low-rise multifamily renovation project under LEED NC 2.2." "Yes, the use of ASHRAE 90.2-2007 as the reference standard for EAp2 and EAc1 is acceptable in the described case. This ruling is applicable only to projects that registered before LEED for Homes was released on 02/18/2008. All subsequent projects 3 stories and less should apply under LEED for Homes. ASHRAE 90.1-2004 shall be considered for EAp2 & EAc1 for all other residential buildings under NCv2.2." "None" "None" "LEED Interpretation" "5159" "2008-10-24" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a multi-use complex consisting of 9 total buildings & an underground parking garage. There is a central condenser water plant serving retail spaces with a closed circuit fluid cooler and dual gas fired condensing boilers. Building 1 contains retail space on the street level. Heating and cooling in the retail space is handled by Water Source Heat Pumps served by the central condenser water plant. A theater is located above the retail space. The theater is not served by the central condenser water plant. All utilities associated with the theater are metered separately from the rest of the complex. The theater is being built under a separate building permit and is not part of the LEED scope of this project. Buildings 2 & 3 contain office space and retail space on the street level and 5 floors of residential apartments above the street level. Heating and cooling in the office and retail space is accomplished via Water Source Heat Pumps served by the central condenser water plant. The apartments are heated with electric heat and have no air conditioning. Buildings 4 - 9 are 3 story condominiums. The condos are not served by the central water system. The condos are heated via electric heaters and have no air conditioning. In addition there is a 2 story unconditioned underground parking garage that is under buildings 1 - 7. Buildings 8 and 9 are above ground slab on grade. The entire site contains 279 apartment units which utilize 216,764 square feet, 109 condo units which encompass 103,723 square feet, 56,260 square feet of retail/office space, and 285,109 square feet of underground parking. The condo buildings account for 38% of the total conditioned space. The design team is proposing to include the condos in all aspects of the LEED certification. However, since ASHRAE 90.1 does not apply to low rise multi-family residential buildings of 3 stories or less, we propose to use the Seattle Energy Code, the local governing code, to establish the baseline for the condo buildings. We will perform separate hand calculations for the condo heating/cooling loads, lighting loads, process loads, and fan loads and include these as meter loads in the overall energy simulation to determine the entire site energy cost savings. We will include our condo load calculations in our uploaded documentation. We will also address energy savings associated with the condos in our Narrative for EAc1. We are requesting a ruling to confirm that this approach is acceptable." "The project is inquiring if the condos in the project as described above can be accounted for as a separate energy calculation for the project. As the condos represent only 38% of the total conditioned floor space of what is otherwise a commercial project, and since the project is attempting a single certification for the combined project, the condos need to be included in all energy simulations. The condo buildings must use ASHRAE 90.2 as a performance baseline in the simulations, and the condos must meet the requirements of ASHRAE 90.2. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5161" "2008-10-24" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "This project is a major renovation to the existing building envelope (new skin added, new windows) and to the common area part of a tenant occupied office building. We have received approval from the USGBC to use LEED for New Construction. The core space lighting (elevator areas, lobby, restrooms, conference rooms), ductwork and finishes will be modified but the central air handling system and air cooled chiller and the tenant spaces will be only minimally altered. The question has been posed by the building manager regarding if they need to replace the tenant lighting in the space as the tenant space is not in the scope of work for the project. According to the ASHRAE 90.1-2004 users guide, if you were to replace more than 50% of the lighting fixtures in the building, you would have to meet ASHRAE 90.1-2004 lighting requirements, which, based on our analysis of what the base case and current design is in terms of lighting power density for this office building, means the building managers would have to replace all the tenant lighting with T8, 25 Watt lamps. However, if we replace less than 50% of the lighting in the building, we are not dictated by ASHRAE 90.1-2004, unless the renovation increases installed lighting power. However, according to the LEED Reference Guide for the prerequisite EAp2, lighting applies to all lighting installed on the building site including interior and exterior lighting. If the total installed interior lighting power is lower than the interior lighting power allowance calculated using ASHRAE 90.1-2004, the project complies. These two statements contradict each other if there is less than 50% of the lighting replaced, but the LEED Reference Guide does refer to the ASHRAE 90.1 users manual as a reference. Please advise on what to assume for the tenant space lighting power density in both the base case ASHRAE 90.1-2004 compliant building and the design case if less than 50% of the lighting is replaced." "According to the requirements of the ASHRAE 90.1-2004, Appendix G Table G3.1 section 6, for the proposed case, if a complete lighting system exists, the actual lighting power needs to be modeled. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5166" "2008-11-11" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "Our project, a data center located in Nebraska, can be characterized as typical for a newly constructed data center in the sense that the energy used per square foot is 100 times greater than that of a modern office building. However, in an effort to increase the energy efficiency of this project, our team has implemented several strategies which will appreciably reduce the energy required to operate the cooling equipment. 1. Removing the computer room air conditioning supply fans by allowing the computer server fans to circulate all of the cooling air 2. Using waste heat from the computer room to provide all of the humidification requirements which would otherwise need to be obtained by mechanical means 3. Using optimized direct evaporative cooling and enthalpy controls for the computer room that maximizes and extends the use of outdoor air cooling. This allows for chillers and cooling towers to remain completely off for five months per year 4. Implementing Cold Aisle supply air containment in the computer room. 5. Elevating cooling supply air temperature to the data center - 75F 6. Elevating chilled water supply temperature - 55F We would like to use the LEED v2.2 Exceptional Calculation methodology (ASHRAE Std. 90.1 G2.5) to quantify the process loads reduction generated by our design using the above strategies. We would like to propose that, for the baseline, we use ASHRAE 90.1 2007 as outlined in the Environmental Performance Criteria (EPC) Guide for New Data Centers, DRAFT based on LEED NC 2.2, 03 September 2008. The EPC guide was the result of a collaborative effort that included a diverse group of participants and organizations, including ASHRAE TC9.9, The Green Grid, The Uptime Institute, 24x7, the European Commission, the Critical Facilities Roundtable, and the Silicon Valley Leadership Group. ASHRAE 90.1 2007 more specifically quantifies the energy breakdown of components in data centers including computer hardware, mechanical systems that support computer equipment, and humidification and dehumidification, and our team feels that it would an appropriate baseline for this calculation. We would still use the Building Performance Rating method to calculate our projected savings as outlined in Appendix G of ASHRAE 2007. We would also assume that the point interpolations given in the EPC Guide for New Data Centers (10-34 points possible, written for LEED 2009) would NOT be used, and we would be using the standard point interpolation tables found in LEED v2.2 EAc1 Optimize Energy Performance (1-10 points possible) as required by LEED v2.2. We request clarification on two items: 1. Is the approach we have outlined acceptable for showing compliance with EAc1 Optimize Energy Performance? 2. If it is acceptable, would we be required to use the ASHRAE 90.1 2007 standard in the calculation of EAc2 Minimum Energy Performance and EAc3 Renewable Energy (which would obviously directly relate to the EAc1 credit)?" "The project team is requesting guidance on the baseline definition of a data center building in order to submit process load energy savings through the use of an exceptional calculation method (Section G2.5 of ASHRAE 90.1-2004, Appendix G). The team proposes that ASHRAE 90.1-2007 be used as a baseline, as outlined in the Environmental Performance Criteria (EPC) Guide for New Data Centers, DRAFT based on LEED NC 2.2, 03 September 2008. The proposed baseline is not acceptable. The baseline needs additional justification and the EPC Guide for New Data Centers document can be used as support, but the case needs to stand on its own. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5167" "2009-03-10" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "This CIR is similar to the published CIR 2/2/2007 with a response on 2/26/2007. We are requesting an interpretation relating to hospitals. Our project is a 12 story 480,000 sq. ft. hospital addition with fossil fuel heat. Table G3.1.1A indicates that the baseline system should be packaged VAV with reheat (System 7). ASHRAE 90.1-2004 G3.1.3.13 requires the minimum volume setpoints for VAV reheat boxes shall be 0.4 cfm/ft2 of floor area served. However in many spaces of the hospital the minimum flow rate as required by the AIA guidelines is higher than 0.4 cfm/ft2. Can the minimum turn down ratio be increase to match the minimum requirement of the AIA guideline for the each room where specific values are given, while using 0.4 cfm/ft2 of floor area served in areas where it does not apply? This question is not in regard to the pressurization exception as clearly described in G.3.1.1(c), where those spaces are to be modeled as constant volume system type 3. It is referring to rooms such as patient rooms which require a minimum airflow rate of 6 air changes per hour with no specific pressure relationship requirement, which with a 10 foot ceiling corresponds to a minimum flow rate of 1.0 cfm/ ft2. Without modeling the systems with the same code required minimum airflows, it would be an unrealistic comparison." "The applicant requests clarification on whether minimum ventilation rate may be used rather than 0.4 cfm/ft2 for spaces where the minimum ventilation rate exceeds 0.4 cfm/ft2. Addendum am modifies Section G3.1.3.13 to read: ""Minimum volume setpoints for VAV reheat boxes shall be 0.4 cfm/ft2 of floor area served or the minimum ventilation rate, whichever is larger."" LEED does allow the use of ASHRAE addenda as long as any addendum chosen is used in its entirety, and the LEED submittal documentation specifically references the addendum used. Therefore, it is acceptable for the project to model VAV minimum volume setpoints with the minimum ventilation rate if Addendum am is used in its entirety, and the EAc1 submittal documentation references this addendum." "None" "None" "LEED Interpretation" "5178" "2009-01-12" "New Construction, Schools - New Construction, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "Our project is a new 174,786 square foot refrigerated warehouse with interior offices. The office area will comprise approximately 8,800 square feet of the total building. The refrigerated portion of the building will be unoccupied and fully automated, maintained at -10 degrees Fahrenheit, and will include a receiving dock area maintained at +40 degrees Fahrenheit. For the baseline and actual energy performance calculations utilized for EAc1, we are proposing to calculate the office area and equipment of the building only, and exclude the refrigerated portion of the building. To clarify, the portion of the building under consideration includes the following elements: 1. Freezer Storage Area 2. Receiving Area (cold dock) a. Rail Access Vestibule b. Maintenance Room c. Storage Room d. Refrigerator Equipment Mezzanine e. Fire Pump/Sprinkler Room f. Electrical Room ASHRAE 90.1-2004 Section 2.3 states that the standard does not apply to ""(c) equipment and portions of building systems that use energy primarily to provide for industrial, manufacturing, or commercial processes."" The ASHRAE 90.1-2004 User\'s manual reinforces the point ""for example, the Standard does not apply to refrigerated warehouses that are cooled to maintain the quality of the goods stored in the warehouse."" We wish to clarify that for a refrigerated warehouse, the baseline and actual energy calculations for prerequisite EAp2 and credit EAc1 will be based on the office portion of the building only. All energy used for refrigeration in the previously described areas will be excluded from the calculations nor contribute to the required 25% process load. Note however, the envelope portion of the refrigerated warehouse will remain in full compliance with ASHRAE 90.1-2004 section 5. Please confirm that this approach is correct." "The applicant is requesting a waiver from including the refrigerated warehouse from EAp2 and EAc1 calculations. ASHRAE 90.1-2004 does not apply to refrigerated warehouses. This means that there are no minimum efficiency requirements prescribed in ASHRAE 90.1-2004 for these spaces. However, this does not mean that it can be excluded from EAp2 and EAc1 calculations. As per the LEED-NC v2.2 Reference Guide, ALL energy end-uses must be included in the EAc1 calculations. Since the refrigerated warehouse portion of the project is not regulated under ASHRAE 90.1-2004, the applicant must maintain this portion as energy neutral i.e. keep the modeling inputs for that portion identical in both the proposed and baseline models. Applicable Internationally. " "2026, 2301, 5342" "None" "X" "LEED Interpretation" "5183" "2009-02-09" "New Construction" "EAc1: Optimize Energy Performance" "Project description: This is a LEED NCv2.2 registered project. This existing building includes approximately 90,000 sf of university teaching and research laboratory space and approximately 50,000 sf of office and administrative spaces. The building envelope will remain largely intact and interior lab spaces will be modernized at varying levels. Laboratory spaces: Lighting in some labs will be replaced. Chilled water cooling and steam heating are campus infrastructure systems to remain as is. Major upgrades to infrastructure ventilation systems dedicated to laboratories consist of (1) replacing the predominantly pneumatic constant volume controls to digital variable volume controls, (2) replacing distributed individual constant volume fume and general exhaust fans with a building-wide manifold variable volume exhaust system, (3) replacing most of the constant volume fume hoods to variable flow hoods, (4) replacing constant speed variable pitch vane axial fans with variable speed centrifugal fans and (5) reducing room air exchange rates from an average of about 16 AC/HR to an average of about 8 AC/HR. Office/administration spaces: Air handling systems dedicated to office and administration spaces will remain as is. Lighting and interior architecture will remain as is. Credit EA1 Energy modeling: DOE eQuest modeling software is being employed, using ASHRAE 90.1-2004 Appendix G modeling criteria. Appendix G text appears intended primarily for new systems, with some provisions made for existing systems and equipment. Section G.3.1.2 appears geared toward new systems for baseline building design. Table G.3.1 No. 2. allows exclusion of building parts from the models under certain circumstances. Table G.3.1 No. 10(a) provides direction to use actual system types with actual component capacities and efficiencies for Proposed Building Performance. For Baseline Building Performance, Table G3.1 No. 10 provides direction to use section G.3.1.1, which appears to be geared toward new systems. Table G.3.1 No. 10 does not appear to directly speak to Baseline Building Performance in existing systems. Topics to clarify/confirm: #1: Energy model; Baseline Building Performance: Appendix G and Table G.3.1 appear to be structured to model a proposed design against a baseline building of similar type, with various prescribed minimum efficiencies for baseline system equipment and components. Following this structure it seems logical that retrofits to an existing system should be modeled as-designed for the Proposed Building Performance using the existing system for Baseline Building Performance. The LEED NC 2.2 EA Credit 1 text directly cites this Table G.3.1 Section 10(a) text, speaking to use of ""existing system type and actual component capacities"". An alternative approach to Table G.3.1 No. 10(a) Baseline Building Performance, however, is to use the as-designed system component capacities and ASHRAE 90.1-2004 equipment efficiencies, for the baseline model. Doing so, however, may apply the Table G.3.1 No. 10 Baseline Building Performance text, potentially intended for new systems, to existing systems. #2: Modeling of existing systems not modified/included in the project scope: ASHRAE 90.1-2004 Appendix G Table 11.3.1 Section 2. Additions and Alterations allows unmodified HVAC systems to be excepted from the energy performance analysis. Credit Interpretation Ruling 10/16/2008 - provides direction that a LEED project\'s boundary should include all building areas, regardless of degrees/absence of modifications. Proposed actions: #1: Credit EA1 Energy model: Use existing system component efficiencies and capacities for the Baseline Building Model fan systems. These would include fans, pumps and motors in ventilation systems dedicated to laboratory spaces. Use the as-designed component efficiencies and capacities for Proposed Building Performance for modified equipment serving laboratories. Unmodified ancillary pumps and fans serving laboratories would be modeled using existing efficiencies and capacities. #2: Credit EA1 modeling of existing systems serving unmodified office and administrative spaces: Include all building areas in the LEED boundary as clarified in the Credit Interpretation Ruling 10/16/2008, for application to all prerequisites and credits. Omit from the EA1 energy model all unmodified HVAC systems serving office and admin spaces that comply with the ASHRAE 90.1-2004 Appendix G Table 11.3.1 Section 2 exception criteria." "The applicant is requesting clarification of how to apply ASHRAE 90.1-2004 to a combination of renovated and unmodified existing portions of the project. For EAc1, both types of areas must be included in the models and subsequent calculations. The applicant must include ALL energy end-uses in the project scope boundary as per the LEED-NC v2.2 Reference Guide. Please use the following approach- For modified areas/systems: The Proposed Building Performance is calculated as per design. The Baseline Building Performance is calculated as per ASHRAE 90.1-2004 Appendix G requirements For areas/systems not modified: Both the Proposed and the Baseline Building Performance must be modeled as per the existing conditions. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5198" "2009-04-14" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our question deals with selecting the most appropriate space usage and HVAC baseline equipment for non typical rooms for EAc1. The project involves the construction of an airplane hangar facility with a gross area of 26,000 square feet and 2 stories high. The building is comprised of office spaces, metal shops, mechanical room, electrical room, foam room (for fire protection equipment), telecom room and a hangar(with an area of 12200 square feet). A gas fired boiler will provide heating and chiller will provide cooling. The design building systems are as follows: -the office spaces are served by a VAV system with reheat coils -the metal shops are served by constant volume air handling units; the metal shops also have exhaust hoods with dedicated exhaust fans that are interlocked with dedicated 100% make-up air units equipped only with gas fired heat exchanger. -the hangar is heated by an under floor heating system and cooled by 2 rooftop units with direct expansion coils and each sized for half of the total load; the rooftop units are equipped with a gas fired heat exchanger that serves as a backup for the under floor heating system; the hangar will be used as a retrofitting space, meaning that an airplane will be brought in and equipped with various equipment; only attachment/detachment of equipment is performed in the hangar; actual work(preparation, manufacturing) on the equipment is performed in the metal shop rooms adjacent to the hangar. -the foam room is ventilated via a dedicated exhaust fan and outside air intake louver; heating is provided by unit heaters; no cooling provided -the mechanical room is ventilated by a dedicated exhaust fan and outside air intake louver; heating is provided by unit heaters; no cooling provided -the electrical room is ventilated by a dedicated exhaust fan and heated by a unit heater; no cooling provided -the telecom room is cooled and heated by a dedicated heat pump split system -stairways are heated by finned tube radiators; no cooling provided -the elevator machine room is cooled by a fan coil unit; no heating provided -janitors room and toilets are provided with a dedicated exhaust system; no cooling or heating is provided; -mixed shower/toilet rooms are provided with a heating and cooling system through a VAV box. For EAc1 we will use ASHRAE 90.1 Performance Rating Method make the following assumptions: 1. Baseline HVAC System: System 3 PSZ-AC 2. Space usage classification for the hangar is: ""wood/metal shop"" for ventilation and ""workshop"" for lighting 3. The dedicated 100% outside air make-up air units that serve the metal shops and are interlocked with the exhaust fans will be included in ""process loads"" category together with the exhaust fans. 4. Process loads generated by the metal shop rooms and hangar equipment will be the same in both baseline and proposed building performance. We have the following questions: 1. In the baseline building performance: should the janitors rooms, toilets, mechanical, foam and electrical rooms and stairways be served, individually, by system 3? 2. If the telecom room will be served by a heat pump system can the baseline building system be system 4 PSZ-HP (only for this room)? 3. Is our space usage classification for the hangar correct? Due to the fact that the metal shop work is performed not inside the hangar area, can the hangar room be classified as a ""warehouse""(for ventilation purposes only)? 4. If our space usage classification for the hangar area is incorrect, please recommend one, for both lighting and ventilation. 5. Are our assumptions correct?" "The applicant is requesting clarification regarding baseline HVAC system selection and space usage classifications for a manufacturing assembly and office facility. Responses to the individual questions are as follows: 1. Please refer to the zoning requirements in Table G3.1 Numbers 7 and 8 of ASHRAE 90.1-2004 for additional clarification regarding designation of thermal blocks in the energy simulation. 2. All zones with electricity as the primary heating energy source (or un-heated zones) must be modeled using System 4 - Packaged Single Zone Heat Pump per Table G3.1.1A of ASHRAE 90.1-2004. All zones with electricity as the primary heating energy source must be modeled using System 3 - Packaged Single Zone Air Conditioner with a fossil fuel furnace. 3. The ""warehouses"" occupancy category from ASHRAE 62.1-2004 is a reasonable assumption for determining the minimum required ventilation in the hangar space. 4. Not applicable per the response to question 3" "None" "None" "LEED Interpretation" "5206" "2009-05-21" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "We have a question concerning how to draw the LEED project boundary of the C&S project described below. The goal of our client is to develop a sustainable shopping center and therefore planning has been executed with high standards of green building design. The scope of the project is a shopping center that is being built on a previously developed site in an urban environment. Some areas of the shopping center are built under ground level and one part extends underneath an old office building located on the site. There are also two residential buildings being constructed as a separate project on top of the shopping center. This is an example of building stacking, which increases development density and enhances community connectivity. Question: Can the office and residential buildings left outside the LEED project boundary despite the fact that the buildings are physically attached to the shopping center? Justification: The shopping center, the office building and the residential buildings form their own legal entities. In the country where the project is located the real estate register is 3-dimensional and the buildings are legally seen as separate real estate. Therefore the shopping center developer does not have control over the office building located and the residential buildings being built on top of the shopping center. The bottom floor of the office building is detached from the office building, rebuilt and attached to the new shopping center, but the rest of the office building is not within the scope of the shopping center development project and will be left as it is. The construction of the residential buildings is a totally separate project with a different time schedule and constructor. If the buildings were built side by side there would not be any doubt about project boundaries. Locating the office and residential buildings on top of the shopping center instead of being built side by side increases development density and enhances community connectivity. We see that the shopping center solely forms a LEED project in this case." "Based on your description of this specific project, the office and residential buildings could be excluded from the LEED project boundary, as long as the separate buildings do not commonly share energy systems. For energy modeling purposes, the shopping center would need to consider any potential energy reduction benefits (shading, blocking wind, etc.), from the existing office building or projected residential buildings, in the baseline and proposed case. It is essential that these ""unregulated"" components are consistent between the two models. It is pertinent to note that the exclusion of the office and residential buildings from the analysis is purely related to their location vis-" "None" "None" "X" "LEED Interpretation" "5208" "2009-04-27" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Project is pursuing EA Credit 1 points under OPTION 3 - PRESCRIPTIVE COMPLIANCE PATH: Advanced Buildings Core Performance Guide. The proposed building is a 50,000 sq. ft. office building located in climate zone 3a. According to ASHRAE Standard 90.1 2004 an air-side or water-side economizer is not required, although the project will utilize water-side economizers. Section 2.13 of the Core Performance Guide details performance and operational requirements of air-side economizers but does not mandate the usage thereof. We have three related questions: 1) Must a project have air-side economizers to comply with Section 2.13 of the Core Performance Guide? 2) If an economizer is required, can a water-side economizer be utilized in lieu of the air side economizer. 3) The EAc1 Template does not make provision to document Option 3. What documentation and template format is required in order to document the points claimed under Option 3?" "The applicant is requesting clarification to various economizer related issues associated with NBI\'s Core Performance Guide. The following responses address the number items in the request. 1) Yes, air-side economizers must be installed. Section 2.13 of the Core Performance Guide states the purpose of the requirements and criteria are established to ensure the proper performance of outside-air (OA) economizers. 2) No, water-side economizers are not an acceptable equivalent to air-side economizers. 3) It is recommended that for submission a signed LEED EAc1 Submittal Template declaring compliance with Option 3, a document comparing and supporting, at minimum, that prescriptive requirements stated in sections one and two of the Core Performance Guide have been satisfied. Above these requirements, it will be left to the discretion of the team if additional documentation is needed to support credit compliance. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5210" "2009-04-27" "New Construction" "EAc1: Optimize Energy Performance" "The Power Plant Expansion project is an expansion and addition to the existing boiler, chiller and power plant building at a Medical School campus. The project is seeking certification under LEED for New Construction v2.2. The main purpose of the addition and expansion will be to house new high pressure steam equipment, a water chiller, and an electric generator. This new equipment will be sized primarily for the new 300,000 SF R&D/lab/office building being designed for the campus, and there will also be some redundancy/back-up capacity for the existing plant equipment. There will be some accessory control spaces and workshop spaces to service the new plant equipment. There will also be a small (5,000 SF +/-) addition to the opposite side of the building for office space. Please confirm that the following project approach will be acceptable to USGBC for LEED EAC1 compliance and certification: We propose to include only the energy used to heat, cool, ventilate, and light the LEED project areas in the EAc1 energy model, in accordance with ASHRAE 90.1-2004, Appendix G. We will also include domestic hot water generation as normally calculated in LEED models. We propose that the energy input into the steam boiler, chiller and generator, and the energy output from the building (in the form of steam, chilled water, and electricity feeding the campus) be considered process energy, because the purpose of the new equipment and the new space is to create steam, chilled water and electricity for the other buildings on campus. We will need to include the impact of the net process energy on the systems within the project area (for example, the heat output from the boiler will need to be ventilated out of the boiler room, and it may be an opportunity for heat recovery). If we cannot use this approach, the large quantity of energy used in the boiler plant space to make the steam, chilled water, and electricity for the campus will dwarf the small amount of energy needed to maintain HVAC, lighting and domestic hot water in the project area. It will be extremely difficult for the energy model to show the required energy savings for LEED certification." "The applicant is requesting clarification that the energy generated (steam, chilled water & electricity) from a campus plant be considered process energy. Power generated within the plant building and distributed to other campus buildings may be considered process energy while applying the benefit to any uses within the plant building. However, resultant heat generated that is used for the energy systems of the plant building will not be termed process energy, and will have to be considered in the energy model in accordance with the CHP document. As such the plant building should only account for energy consumption of district thermal energy and district power generated that will be used within the building. Refer documents on District Energy Systems and Combined Heat & Power Systems to apply the guidelines. The documents can be found on the USGBC web-site at the following URL: http://www.usgbc.org/ShowFile.aspx?DocumentID=4176 and http://www.usgbc.org/ShowFile.aspx?DocumentID=1354 Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5224" "2009-07-16" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project in question is an existing office building of which everything was demolished with the exception of the structure, slabs and roof. The building\'s skin was reconstructed and the mechanical systems were redesigned. The question is regarding the baseline model calculations used in the Energy and Atmosphere Credit 1 - Optimize Energy Performance. The credit requirements for Whole Building Energy Simulation say to use the Performance Rating Method in Appendix G of ASHRAE/IESNA 90.1-2004 to establish baseline building performance. One of the requirements of this standard (G4.1A - Baseline Building Envelope Orientation) states that ""the baseline building performance shall be generated by simulating the building with it\'s actual orientation and again after rotating the entire building 90, 180, 270 degrees, then averaging the results."" This requirement makes sense when talking about a building in new construction because you have the option to orient the building in such a way as to take maximum advantage of passive solar design, wind currents, etc. With an existing building the existing orientation is already determined so it doesn\'t make sense to establish a baseline off of the average of four orientations. When we model it this way we lose 6% of our energy reduction compared to the design case. We would like to ask if based on the fact that this building\'s orientation was already set because it is a rennovation project, that we can establish the baseline energy model solely off of that building orientation, not the average of all 4." "The applicant is asking if the project can be exempted from the rotation requirement of ASHRAE 90.1 Appendix G. Given the existing nature of the building, it would appear that the existing orientation, as well as the existing envelope would fall under the ASHRAE Appendix G Table 3.1, 5f requirement for Existing Buildings that states: ""For existing building envelopes, the baseline building design shall reflect existing conditions prior to any revisions that are part of the scope of work being evaluated"" Given that the existing building is already situated as stated in the CIR this set existing condition can be modeled as constant in the baseline. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5234" "2009-08-31" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "This credit interpretation request is regarding the baseline system selection. The project is a campus classroom/laboratory building in Grand Junction, CO. The proposed building HVAC system is composed of distributed water source heat pumps served by a district geothermal condenser water loop. The district geothermal system has enough ground wells such that nearly all condenser heating and cooling loads will be met. However, there are gas fired boilers and cooling towers in place that will help to maintain loop temperatures during peak heating and cooling conditions. Our confusion is that the campus district cooling and heating system falls under the document, ""Required Treatment of District Thermal Energy in LEED-NC version 2.2 and LEED for Schools."" However, this document does not address the case of a district condenser water loop. If we were to follow Appendix G ignoring the fact that the building is served by a district condenser water loop, the system falls under the category of a hybrid system and ASHRAE 90.1-2004 Appendix-G dictates that the baseline system should be System 5 - Packaged VAV w/ Reheat. When we compare the baseline and proposed systems, this appears to be a clear case of fuel-switching. The proposed system is 90% or more electric heating, while the baseline system is 100% natural gas heating via hot water boilers. We are proposing to use the ""Energy Cost Budget"" method for determining the baseline system as detailed in ASHRAE 90.1-2004 section 11. Based upon figure 11.3.2 in ASHRAE 90.1-2004, the baseline system would be System 6 -Heat pumps on a condenser loop with boilers and fluid coolers. Note 7 of Table 11.3.2.A describes System 6 and the water-source heat pumps assumptions. We would use the electricity and gas rates paid by the campus in both models rather than following Steps 1 and 2 in the document, ""Required Treatment of District Thermal Energy in LEED-NC version 2.2 and LEED for Schools."" The air distribution system in both models would be through distributed heat pumps served by the condenser water loop." "The applicant is requesting guidance for a building which receives condenser water for Heat Pumps within the building from a district geothermal loop (with supplemental cooling tower and boiler operation). The applicant is requesting that the system be removed from the ""District"" energy guidelines as well as the Appendix G Baseline system type and be allowed to use the ASHRAE Energy Cost Budget (section 11) methodology to define the Baseline system. It appears, based on the description, that the building does not fall under the District Energy requirements, in that it is not provided with cooling or heating from a district source, but rather provided with condenser water which feeds heat pumps that produce the cooling and heating within the building. As such it is not required to follow the methodology defined in the ""Required Treatment of District Thermal Energy in LEED-NC version 2.2 and LEED for Schools."" The project is also requesting exemption from the ASHRAE Appendix G system definition and to instead use the ECB method. According to LEED protocol, all projects following ASHRAE must use the Appendix G methodology, therefore this request is denied. The entirety of the Appendix G protocol must be used, including the Baseline system definition as determined by Table G3.1.1A. The project team may decide to pursue exceptions to this Table as identified in the ""Exceptions to 3.1.1"" portion of Appendix G, however it is uncertain if these will apply to the project. It would appear that the project should compare the design as described, to the appropriate system identified in Table G3.1.1A." "None" "None" "LEED Interpretation" "5235" "2009-06-30" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EAc1: Optimize Energy Performance" "Our project consists of multifamily rental units. We are performing the energy model using TRACE 700, a program that meets ASHRAE Standard 140-2004: Building Thermal Envelope and Fabric Load Tests. TRACE 700 does not have the capability of modeling domestic hot water energy usage. In order to account for domestic hot water energy usage we are proposing to use the Department of Energy sponsored Lawrence Berkeley National Laboratory calculation methodology. The spreadsheet can be found at www.doa.state.wi.us/docs_view2.asp?docid=2249. This spreadsheet estimates the energy consumption of water heaters based on power source, energy factor, and recovery efficiency. In addition, the spreadsheet estimates the energy reductions associated with hot water consumption of Energy Star clothes washers and dishwashers. According to the CIR ruling dated 4/25/2007, credit cannot be taken for low flow fixtures accounted for in WE credit 3. However, clothes washers and dishwashers are not accounted for in LEED NC v2.2 WE credit 3. An exceptional calculation in accordance with Appendix G will be provided to demonstrate energy savings for the Energy Star appliance itself. In addition, we believe the reduction in the amount of hot water required by Energy Star clothes washers and dishwashers should be accounted for in the water heating calculation. The basis for these calculations found at http://hes.lbl.gov/hes/aboutwhm.html will be uploaded as supporting documentation. 1. Can we use the Lawrence Berkeley National Laboratory spreadsheet since TRACE 700 does not model energy consumption for domestic water heaters? 2. Can the energy savings for the reduced hot water consumption for Energy Star clothes washers and dishwashers be accounted for in the domestic hot water energy consumption calculation?" "The applicant is asking for confirmation that LBNL spreadsheet calculations can be used to document domestic hot water use and asking if hot water savings resulting from Energy Star clothes washers and dishwashers can be accounted for in the exceptional calculation. 1. It seems that the LBNL spreadsheet calculations are an appropriate method for calculating domestic hot water use and for documenting the energy savings associated with Energy Star equipment. However in order to be accepted as an exceptional calculation, be sure to include a detailed narrative with all assumptions and supporting calculations with the submittal. 2. Yes, energy savings for reduced hot water consumption can be counted in DHW energy calculation. ***Please note, this CIR was updated on 7/10/2009.***" "None" "None" "LEED Interpretation" "5253" "2007-03-23" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a multiple building high-end condominium-resort project. This question relates to the requirements of lighting as it pertains to ASHRAE/IESNA 90.1-2004. In ASHRAE 90.1-2004, section 9.1.1, exceptions (b) lists that this section does not apply to lighting within living units. However table 9.5.1 Lighting Power Densities Using the Building Area Method lists ""Multi-family"" building area type with a 0.7 W/SF. Please clarify for the purposes of EAp2 and EA credit 1, the applicable interpretation of the Standard. Does the entire building have to meet the 0.7W/SF requirement as an average?" "The applicant is requesting clarification regarding which lighting is included in the allowable lighting power density for high-rise multifamily residential projects. All common areas and support areas including circulation, lounges, lobbies, etc. should be included in the lighting power density calculations. Therefore, when using the Building Area Method, the average lighting power density for common areas and support spaces in a high-rise condominium project should be modeled as 0.7 Watts/sf in the Baseline case; or when using the prescriptive compliance methodology, the average lighting power density for these spaces should not exceed 0.7 Watts/sf. Dwelling units are excluded from the allowable lighting power density. For EA credit 1, the exception listed in Table G3.1.6 states that lighting in multifamily guest rooms which are connected via receptacles and are not shown on the building plans should be modeled identically in the Baseline building and Proposed building simulations, but should be excluded (in post-processing) when calculating the Baseline building performance and Proposed building performance. For EA credit 1, all hard-wired lighting in living units that is shown on the building plans should be modeled identically in the Baseline and Proposed building simulations as shown in the plans. This lighting shall be considered process energy. Credit may be taken for an efficient lighting design in the living unit using the Exceptional Calculation Methodology shown below. (1) Assumptions used as a baseline for residential lighting will need to be supported by specific study results if you propose to include residential lighting savings in the energy performance calculations. These studies will need to address both light density AND daily duty cycle. The maximum allowable baseline for such residential lighting is restricted to 2 W/sf. (1) Although residential lighting density is higher than offices, the duty cycle of these lights is much lower than in offices. Some studies suggest figures near 2 hours a day or less for hard-wired residential fixtures. This reduces the significance of residential lighting in the energy model. (2) Baseline lighting assumptions should not include \'portable\' light fixtures, nor should the baseline calculations assume use of hard-wired fixtures in rooms where the studies cited indicate portable lights are the norm. Therefore applying a factor of 2 w/sf to the entire residential floor area, even though only three rooms would be anticipated to have hard-wired fixtures, would be inappropriate. In other words, lighting credit can only be taken in rooms where permanently installed hard-wired lighting fixtures can meet the illumination requirements for the room. (3) In residential units which are heating-load driven, there is an energy offset penalty of approximately 40% (according to numerous Pacific Northwest studies) for reductions to residential lighting load. That is, 4 of every 10 watts saved by reduced lighting loads must be made up for by increased heating energy. This offset must be accounted by your model. (4) Use of residential lighting energy savings to achieve LEED credit represents an exceptional calculation methodology outside of the LEED modeling protocol. As such it will be carefully scrutinized with respect to baseline and performance claims, and clear and concise documentation will be expected. The energy submittal template must account for this measure using the Exceptional Calculation Methodology." "None" "None" "LEED Interpretation" "5261" "2007-04-25" "New Construction" "EAc1: Optimize Energy Performance" "The adoption of Appendix G under LEED 2.2 raises all sorts of interesting questions with respect to the energy modeling protocol. Please clarify for us and the world of LEED users out there the following: 1. Appendix G Addendum a Would USGBC for LEED 2.2 adopt the published Addendum a to 90.1-2004 Appendix G which changes a number of areas? 2. Building Orientation May we choose to not implement in our baseline model ASHRAE 90.1-2004 Appendix G Table G3.1 5. (a) orientation rotation which requires rotating the model to 4 cardinal directions, and averaging the results. For our project, orientation with the long axis of the building East-West was not optional. 3. Baseline Fenestration Area and Location Would the USGBC eliminate the provision under ASHRAE 90.1-2004 Appendix G Table G3.1 Baseline 5.(c) that requires dividing out the entire design window area, up to the 40% maximum window to wall ratio, and defining it as horizontal bands with average window to wall area on all facings and floors? This change is also proposed under Addendum a to 90.-2004. The addendum references the section numbering from an earlier version of the Standard prior to the creation of Table G3.1 in the current version of the Standard. 4. Residential Designed Lighting Baseline Will USGBC for LEED 2.2 adopt the same rules adopted under LEED 2.1 CIR rulings that established a residential lighting baseline, for designed fixed lighting? ASHRAE 90.1-2004 still treats residential living area lighting as exempt (9.1.1 Exception b), and Appendix G does not define a baseline for this lighting. The rulings defined a process of mapping from the designed lighting to baseline lighting with conventional incandescent lighting, with a maximum baseline lighting power density of 2.0 W/s.f. The rulings also established a 750 hour full load equivalent operating schedule to be the same in design and baseline. 5. Residential Receptacle Lighting Will USGBC for LEED 2.2 accept 90.1 Addendum a) change to table G3.1 Design 6 (d) so that receptable lighting energy usage is not subtracted out from the design and baseline models. This is an inconsistency the addendum corrects, and is the only case where non-regulated energy is not counted under the new standard. 6. Lighting Controls Will USGBC for LEED 2.2. allow Exceptional Calculations regarding energy savings for occupancy sensor and time-of-day controls that exceed ASHRAE 90.1 code requirements that are greater than the Appendix G Table G3.2. For example, LEED 2.1 rulings appeared to allow greater than 10% allowed by Appendix G for occupancy sensors controlling normally 24 hour interior stair lighting in a multi-family high-rise that would be occupied only a small fraction of the time. 7. Exterior Lighting Will USGBC for LEED 2.2 allow credit for exterior lighting that is more efficient than the new mandatory provision for exterior lighting in 90.1-2004 section 9.4. Appendix G does not address how exterior lighting should be modeled for the baseline, and therefore the default is that it should be modeled the same as the design and no credit for savings could be taken. 8. Residential Appliances and Exhaust Fans Will USGBC for LEED 2.2. allow for Energy Star rated appliances and exhaust fans an Exceptional Calculation approach (similar to previous LEED 2.1 rulings for an appliance ID credit) to calculate energy cost savings for EAc1? Exceptional calculation would be based on Energy Star data to define design and baseline energy usage? 9. DHW Usage Reduction Will USGBC for LEED 2.2. allow the approach to claim domestic hot water energy cost reduction based on low flow fixtures, relative to EPACT standard allowed fixture flows from earlier LEED 2.1 rulings. Another approach would be to adopt 90.1-2004 addendum a) revision to Table 3.1 Baseline 11. labeled as a revision to G4.3 under the older numbering convention. 10. Heat Recovery from Condenser Loop Will USGBC for LEED 2.2 allow the baseline adjustment for heat recovery from condenser loops to DHW as required in section 6.5.6.2 to be done with assistance of spreadsheet analysis outside of the model, or will the provision at Appendix G Table 3.1 Baseline 11 (f) exception that requires the proposed design to actually include the heat recovery equipment in the real building, if the modeling software cannot model it. The design feature cannot be modeled under DOE-2.2 and its interface eQuest, one of the most widely used and otherwise versatile programs. This provision, if enforced, requires a significant expense for the project that may not be cost effective compared to alternatives. This would be a penalty on the subset of projects that fall under the rules at 6.5.6.2. Normally, the design does not have to meet the prescriptive requirements of ASHRAE, but is allowed to make trade-offs to achieve overall energy cost savings. 11. Solar Hot Water-Clarify Eligibility for EAc1&2 Will USGBC state that solar hot water generation, that does not generate any electricity is eligible for credit under EAc1 and EAc2? Requirements language paragraph 1 for EAc2 does not state if energy generated from a renewable source is electric or thermal, although other parts of the chapter allow for solar hot water, but the second paragraph refers to a method to just estimate electricity generation. Just want to be sure there is no question that solar hot water generation is eligible for both EAc1&2." "[REVISED 10/30/07 to allow energy savings for exterior lighting.] 1. No. Since multiple projects are already in process and the LEED-NC v2.2 Reference Guide specifically mentions that ASHRAE 90.1-2004 is applicable without addenda; any addenda not included in the completed standard will not be accepted at this time. 2. No. The Appendix G method of distributing the glazing equally on all orientations normalizes this issue. The question raised by Appendix G is - Is your building designed to respond to the specific solar orientation? 3. No. See points 1 and 2 above. 4. Yes. The calculation methodology should be considered equivalent for LEED-NC v2.2. 5. The LEED modeling protocol addresses this issue by setting the process load as 25% of total energy by default, unless it is a process dominated building. For a typical residential building, process loads will never be above 25% and therefore should not be an issue. 6. Exceptional Calculation for any measure that is not accounted for in the modeling protocol is accepted on a case-by-case basis. 7. Yes, project teams can take credit for efficient exterior lighting within ASHRAE 90.1 Appendix G. Credit may only be taken for the tradable surfaces listed in ASHRAE 90.1-2004 Table 9.4.5. All other exterior lighting must be modeled identically in the Baseline and Proposed case. The Baseline case exterior lighting power allowance should be calculated using the methodology outline in Section 9.4.5. 8. Yes. Page 184 of the LEED-NC v2.2 Reference Guide describes Exceptional Calculations for residential appliances. 9. No. Credit for saving water is already granted in the Water Efficiency section of the LEED Rating System. The Domestic Hot Water (DHW) loop will be sized for design flows and the PRM does not allow credit for changing loop flows for DHW. 10. No. The requirements for the loop sizing have been set in Appendix G and to maintain integrity of the modeling protocol, such exceptions cannot be taken. 11. Yes. On-site energy generated can be taken credit for using the Exceptional Calculations under EAc1, Optimize Energy Performance, and as percent of total energy for EAc2, On-Site Renewable Energy. Note: ASHRAE Addenda have been approved for use in LEED projects, as stated on our website: http://www.usgbc.org/ShowFile.aspx?DocumentID=2664 Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5275" "2007-09-18" "New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "This project is pursuing EA Credit 1, Option 2. We are using the ""Advanced Energy Design Guide for Small Office Buildings"" (Achieving 30% Energy Savings over ASHRAE 90.1) in lieu of energy modeling, as allowed in LEED NC-2.2. Under the section for ""Envelope / Vertical Glazing / Exterior Sun Control (S, E, and W only)"", the recommendation for our climate zone (5) is a projection factor of 0.5 for a window with an SHGC of 0.46. Rather than providing exterior shading, we are proposing to use a window with a lower SHGC that will achieve similar performance. This approach is based upon Table 5.5.4.4.1 ""Solar Heat Gain Coefficient Multipliers for Permanent Projection"" from ASHRAE 90.1-2004, that lists multipliers for projection factors to meet Solar Heat Gain Coefficient requirements. To achieve a Projection Factor of 0.50, Table 5.5.4.4.1 gives an SHGC multiplier of 0.67 to arrive at the adjusted SHGC. The design guide requires an SHGC of 0.46 with a projection factor of 0.5 for our climate. Multiplying the SHGC of 0.46 by 0.67 gives an adjusted SHGC of 0.28. This project is proposing to use a window that meets the SHGC of 0.28 and eliminate the need for exterior projections." "The project team has requested an alternate compliance path for documenting fenestration performance in conjunction with the ""Advanced Energy Design Guide for Small Office Buildings."" This alternate compliance path would allow exterior shading to be omitted from the project by decreasing the SHGC. The compliance approach outlined above is acceptable. Please use the projection factor for "">0.50-0.60"" (0.61) rather than the projection factor for >0.40-0.50 (0.67) described above. Also, provide a narrative with the submittal referencing this CIR, and documenting the revised SHGC requirement for the project\'s climate zone, as well as the installed SHGC. * Note: The ASHRAE Energy Design Guide for Small Office Buildings"" was developed based on ASHRAE 90.1-1999, and the corresponding ""SHGC Mulipliers for Permanent Projection Factors"" table for ASHRAE 90.1-1999 is in Table 5.3.2.3. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5288" "2008-02-22" "New Construction" "EAc1: Optimize Energy Performance" "The project is a 3-story, 18,000 SF, mixed use building that is one-third office space and two-thirds retail space, located in The Woodlands, Texas. Despite the mixed use of the building, is it acceptable, under Option 2 - Prescriptive Compliance Path, to classify this building as an office occupancy, and achieve 4 points through compliance with the prescriptive measures of the AHSRAE Advanced Energy Design Guide for Small Office Buildings 2004? Please note that ASHRAE has developed an Advanced Energy Design Guide for Small Retail Buildings 2006. Due to the fact that the project will not have a heated slab, the requirements listed for Climate Zone 2 in the Advanced Energy Design Guide for Small Office Buildings 2004 are more restrictive than the aforementioned Design Guide for Small Retail Buildings. Therefore, if the building is allowed to be classified as a small office building as stated above, the retail component of the mixed-use building would be constructed to a more stringent and energy efficient standard." "Because only one-third of the building is office, this project cannot use the Advanced Energy Design Guide for Small Office Buildings. Also, the Advanced Energy Design Guide for Small Retail Buildings is currently not available as a compliance path. See http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1734 for the potential application of the LEED for Retail Rating System. This project can pursue Option 1 -- Whole Building Energy Simulation or Option 3 - Prescriptive Compliance Path: Advanced Building Core Performance Guide. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5293" "2008-02-11" "New Construction" "EAc1: Optimize Energy Performance" "Our project is an aquatics center owned and operated by the City of Henderson in Nevada. The adjacent property has a senior center also owned by the City. Both buildings are being designed by two separate A/E teams, and are registered as separate LEED projects. For contractual reasons the two buildings need to be submitted as separate LEED projects. However, the two buildings share a heat-pump building loop that will either be connected to a cooling tower/boiler central plant or an underground well-field loop. The sharing of the building loop is intentional since it allows both buildings to reject heat to the pool water. The sharing of the central plant/ well field also allows the two buildings to take advantage of the diversity of loading of the two buildings in sizing the heat rejection capacity. In this scenario, modeling either building separately will fail to accurately account for the way the loads are shared across the two buildings; especially the heat rejection into the pool water. Hence, we propose to build a common energy model for the baseline and design for both buildings and establish energy savings and estimate the EA Credit 1 points for the combined model. We would then apply these estimated points to both buildings. Conceptually this is the reverse of a campus energy approach where you are allowed to do a weighted average of separate building energy models to for EA Credit 1 for the entire campus. In this case there will be a common model that will be used to document EA Credit 1 for two separate LEED projects. From the perspective of either building, doing this averages the energy performance across the two buildings; and one of the buildings is likely to lose some energy efficiency and the other will gain some. The owner and design teams are ready to live with this. Since the energy model more closely reflects the building this approach allows for a more accurate model and energy estimates, and also sets up the correct model for the comparison with the energy data for the M&V Credit. We would like you to confirm that this approach is acceptable." "The CIR is requesting permission to use a single energy model that incorporates two separate facilities (with shared mechanical systems) in the submission of two separate LEED registered projects. Normally a project team should use the methodology described in the LEED-NC Application Guide for Multiple Buildings and On-Campus Building Projects (hereby referred to as the Multiple Buildings App Guide) or in the LEED-NC v2.2 EAc1 CIR Ruling dated 11/3/2006. However these methodologies assume a standard central-plant set up, where each building only interacts with the central plant. In this case it is acceptable to create an energy model with both buildings in the same model, and thus effectively create a single ""facility"" with the same end result for EAc1 applied to each building ONLY because there is direct energy transfer between the two buildings that could not be represented using a standard central plant. Guidance for larger facilities connected to a central plant or with shared systems is forthcoming. The separate projects will have to submit for certification using the methodology outlined in the Multiple Buildings App Guide section titled ""Certifying new buildings where each new building is constructed to a set of standards but will receive an independent rating based on achievement of credits beyond the standards,"" which will have to specifically be arranged with USGBC staff prior to the first building being submitted.\n\nUpdate April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues. " "None" "None" "LEED Interpretation" "5297" "2008-03-13" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our project is a science and technology lab building on the University of Nevada Las Vegas Campus of approximately 181,000 sf, with a 1200 sf greenhouse for experiments. The greenhouse has four cells which will mimic the exact environmental conditions of the Nevada (nuclear) Test Site as they occur in the open desert. Thus the greenhouse cells will be conditioned to match the exact temperature and humidity conditions at the test site; lighting will also match the conditions at the test site. This is being accomplished with a system separate from the rest of the lab building. Since the greenhouse conditioning and lighting is for the purpose of carrying out experiments, it is similar to a lab hood or other lab process equipment. We will treat the energy use from lighting and conditioning the greenhouse as a process load in the Energy Cost Budget Method model and subtract it for calculating the percent energy savings. Please confirm that this approach is acceptable." "Based on the description above, it appears that the energy use would most likely be considered process related and therefore could be excluded from the Energy Cost Budget (ECB) Method model. ASHRAE 90.1-1999 defines process energy as ""energy consumed in support of manufacturing, industrial, or commercial process other than conditioning spaces and maintaining comfort and amenities for the occupants of a building."" Please note that if any of the energy use in the greenhouse is deemed as necessary for the comfort of occupants (lighting, auxiliary heating, etc.) and is not associated with the lab related experiments, then it would need to be included in the ECB calculations as a regulated energy use. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5312" "2008-04-23" "New Construction" "EAc1: Optimize Energy Performance" "Our question is in regards to 1) the baseline HVAC system selection and 2) modeling a variable air volume strategy for a bus maintenance and bus storage facility. The facility is a 20,500 square foot bus maintenance and 128,600 square foot bus storage facility (plus administrative space which is outside the intent of this question). The bus maintenance is heated to 68 F; the bus storage is heated to 45 F. The exhaust requirement by code is 1.5 cfm per square foot. The bus maintenance area is ventilated by heating and ventilating units and exhaust fans with heat recovery. Additional heat is supplied to the bus maintenance with radiant heat from an underslab hydronic system. The sequence of operation for supply and exhaust fan control uses a combination of space temperature and carbon monoxide and nitrogen dioxide sensing to vary the fan speed and the amount of outside air of the heating and ventilating units and fan speed of the exhaust fans. The heating and ventilating units will operate most of the time in a recirculating mode with 10% to 20% outside air and at reduced fan speed, generally 50% of design air flow. Exhaust fans do not run continuously. The heating and ventilating units are estimated to run for nine hours per day in the bus maintenance. Significant outside air quantities are estimated to be required less than one hour per day on a cumulative basis. Bus Storage is served by dedicated make-up air units which are off unless high carbon monoxide or nitrogen dioxide levels exist. Bus storage is heated by ducted combustion air and high efficiency unit heaters. Based on typical times that buses run in the storage area, the make-up air units will likely run for less than 6 hours per day on a cumulative basis which includes a purge cycle of about five minutes each hour during regular operating hours. Per ASHRAE Standard 90.1-2004, the baseline HVAC type is assumed to be:  Bus maintenance: System 3 - Packaged Single Zone - AC with heat recovery  Bus storage: System 5 - Packaged VAV with Reheat (no heat recovery). We are using a DOE-2 based software to vary air volume (except the baseline for bus maintenance which is constant volume) based on space temperature for both the baseline and proposed building performance as a reasonable approximation of the space temperature, carbon monoxide and nitrogen dioxide profile which is unknown. Please confirm that  the baseline system selection for bus maintenance and bus storage is correct  the schedule for HVAC equipment in bus storage can use a reasonable assumption based on typical times that bus engines will be running for both baseline and proposed building  the air flow and fan speed for the maintenance area can be modeled based on space temperature for both the baseline and proposed building performance." "The applicant is requesting verification regarding their selection of Baseline System Type for the project, as well as their intended method for modeling the HVAC equipment schedules, air flow, and fan speed. 1. If the bus maintenance facility and bus storage facility are part of the same building, they should be modeled with the same system type, using any applicable exceptions listed in G3.1.1. The total square footage reported for the bus maintenance and bus storage facility is 149,100. If the administrative spaces result in the total building conditioned area exceeding 150,000 square feet, the project would be modeled using System Type7 - VAV with Reheat. 2. If the bus maintenance facility and storage facility are two separate buildings, the System Type may be modeled differently for each building, based on the total conditioned square footage of each individual building modeled. If the total square footage of the Bus Maintenance building is less than 25,000 square feet (if using Addendum a or 2007 Appendix G) or less than 75,000 square feet (if using Appendix G without Addenda), the appropriate system type would be System Type 3 - PSZ-AC. If the Bus Storage building is less than 5 stories, and less than 150,000 square feet, then the appropriate system type would be System Type 5 - Packaged VAV with reheat. For spaces that do not have cooling installed, cooling must be modeled in the Proposed Case using the identical cooling system type, cooling efficiencies and temperature schedules modeled for the Baseline Case (Table G3.1#10(Proposed)). Exhaust air energy recovery shall be modeled the Baseline Case of the Bus Maintenance facility wherever G3.1.2.10 applies (Note: if desired, the project may use the language from ASHRAE 90.1-2007 Appendix G in place of ASHRAE 90.1-2004 Appendix G, which would allow heat recovery to be excluded for the Baseline case for the bus storage facility systems since these systems are not cooled and are heated to less than 60 deg. F. If this option is selected, the project must follow the language of 2007 Appendix G in its entirety). It is reasonable to model HVAC equipment schedules based on a six-hour per day expected run time as indicated above. The schedules should be modeled identically in the Baseline and Proposed Case. It is unclear how modeling space temperature variations to meet temperature loads will adequately approximate the space temperature, carbon monoxide and nitrogen dioxide profile. Further information is required regarding this strategy in order to verify its appropriateness for this application, or to verify that any credit can be documented using this Exceptional Calculation Method strategy. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5313" "2008-05-27" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our project is a Graduate University located in Saudi Arabia dedicated to the research of alternative fuels and renewable energy. The entire campus will be New Construction and will consist of research labs, lab support areas, administration buildings, a library, a commons building, food service, an auditorium, conference rooms, lecture halls, offices and public areas. The Campus will also contain a Greenhouse structure. Since the ASHRAE Standard 90.1-2004 does not apply to buildings or portions of buildings that use energy primarily for commercial of industrial processes, our project team is proposing that the energy use in the greenhouse would most likely be considered process related load for the Performance Rating Method. Energy use in the greenhouse will not be used for occupant comfort. Please confirm that this approach is acceptable." "The applicant is requesting clarification regarding whether energy used in a greenhouse that is part of a campus application should be considered process load using the ASHRAE 90.1 Performance Rating Method. Any of the energy end-uses in the greenhouse that are deemed necessary for the comfort of occupants (e.g. ambient lighting, spot cooling, etc.) should be reported as regulated end-uses. Space conditioning equipment and lighting used primarily to support plant growth functions should be reported as Process energy in the EAc1 template Tables 1.8.1 and 1.8.2. Please be sure to separately report the process space conditioning energy from other process equipment energy. Treatment of Envelope: If the primary function of the building envelope for the greenhouse is to achieve the solar and thermal conditions required for plant growth, the envelope may be excluded from the prescriptive requirements of ASHRAE 90.1; and the envelope should be modeled identically in the Baseline and Proposed Case. [Note: this does not extend to other building types, such as manufacturing facilities, or others, where the envelope is not directly tied to meeting the process functions]. Treatment of Lighting: Lighting should be modeled using the Space-by-Space or Building Area Method, and should apply any applicable exceptions provided for in Chapter 9. For example, Section 9.2.2.3 specifies ""lighting for plant growth or maintenance"" as unregulated lighting, which should not be included in the interior lighting power allowance (this lighting must have a separate control device (Section 9.4.1.4(e)). This lighting still should be included in the energy model as process lighting, and should be modeled identically in the Baseline and Proposed Case. Treatment of Space Conditioning: If the space conditioning / humidity control systems are primarily designed for maintaining the conditions required for plant growth, and are not used to maintain occupant comfort, the space conditioning system type and controls should be modeled identically in the Baseline and Proposed Case. Mandatory equipment efficiencies from Tables 6.8.1A-J, and any other mandatory measures from Chapter 6 with their applicable exceptions do apply to the Greenhouse space conditioning systems. The baseline case process air conditioning system should be modeled as meeting the minimum equipment efficiencies from Chapter 6. The proposed case should be modeled with as-designed equipment efficiencies. An informed determination can only be provided during LEED certification review if the requirements ASHRAE 90.1 Section G2.5 guidance are satisfied (i.e., provide theoretical and empirical information verifying accuracy). Applicable Internationally; Saudi Arabia. " "None" "None" "X" "LEED Interpretation" "5317" "2008-10-03" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1: Optimize Energy Performance" "Conventional vented domestic clothes dryers require approximately 200 cfm of exhaust when operating. In large multi-story residential buildings, the dryer exhaust is typically provided by dryer exhaust risers that vertically link multiple units with a constant or variable speed exhaust fan. Several exhaust risers may be used to meet the needs of all apartments in a building. Variable speed fans typically modulate based on static pressure in the exhaust riser and are limited no less than 25 percent of design flow. Constant speed fans assume some diversity and do not modulate. Either fan operates 24 hours per day. The dryer exhaust requires continuous makeup air that must be conditioned either at an outside air handling unit or as in additional infiltration load in individual residences. An alternative to conventional vented dryers are ventless condenser dryers. Condenser dryers still use heated air to evaporate water from the clothes, but use an air-to-air heat exchanger to condense water from the humid air rather than exhausting the air and replacing it with fresh air from the room. Heat from the dryer remains in the room and no external venting or makeup air is required. Vented dryers are the ""standard practice"" in large residential buildings. This is probably due to the fact that (1) vented dryers are the more familiar technology, (2) drying times are shorter with conventional dryers than with condenser dryers, and also because (3) vented dryers are less expensive than condenser dryers. Based on a 1998 study by James Kao of the National Institute of Standards and Technology (NIST) titled ""Energy Test Results of a Conventional Clothes Dryer and a Condenser Clothes Dryer,"" condenser clothes dryers use between 5 and 30 percent more energy per pound of laundry than a conventional vented dryer (depending on the size of each load). The NIST study only accounts for the energy to operate the dryer. The study does not account for the additional effects on the HVAC system due to the outside air requirements. The net effect of using condenser dryers in lieu of conventional dryers is a reduction in overall energy use in the climate zone for the building we are studying (New York City climate). We propose the following as an exceptional calculation methodology to simulate the performance of condenser dryers over standard vented dryers: Baseline Building: 1. Model typical dryer energy patterns based on standard washing machine use patterns from EnergyStar. 2. Model the dryer such that none of the dryer energy results in heat gain in the space. 3. Model the Baseline Building with 50 cfm of air exhausted from each residential unit with a dryer. To do this, include dryer exhaust fan energy assuming that the fan runs at an average of 50 cfm, 24 hours per day, at the same static pressure as the other rooftop exhaust fans. Include 50 cfm of additional infiltration 24 hours per day for every residence with a dryer. Proposed Building: 1. Increase the dryer energy use by 20 percent based on a conservative rounding of the average results from Kao\'s study of dryer energy use. 2. Model the dryer such that all of the dryer energy results in heat gain in the space. 3. Model the proposed building without the dryer exhaust fans and without the additional 50 cfm of infiltration. Is this exceptional calculation method acceptable for LEED EAc1 credit?" "The applicant is inquiring about the acceptability of a proposed exceptional calculation method that takes credit for using domestic condensing dryers instead of standard vented dryers in a multi-family high rise residential project. Using an exceptional calculation method to determine energy savings is a generally acceptable pathway. However, the information presented is not sufficient to determine if this exact calculation is adequate enough to determine the correct amount of savings (if there is a savings). The design team must provide justification for their specific assumptions in both the baseline case and the proposed case. Baseline Building: 1. Model typical dryer energy patterns based on standard washing machine use patterns from EnergyStar. This is acceptable. 2. Model the dryer such that none of the dryer energy results in heat gain in the space. Assuming no heat gain to the space is not self evident. Documentation in the form of industry accepted studies indicating as such would be required to ensure that this is an acceptable assumption. 3. Model the Baseline Building with 50 cfm of air exhausted from each residential unit with a dryer. To do this, include dryer exhaust fan energy assuming that the fan runs at an average of 50 cfm, 24 hours per day, at the same static pressure as the other rooftop exhaust fans. Include 50 cfm of additional infiltration 24 hours per day for every residence with a dryer. Assuming 50 cfm of continuous ventilation per dwelling may be excessive. A study of use patterns combine with cfm values for expected dryer type applied to this particular building would be required. Calculations on static pressure that include data on the height of the building, the max. static pressure per dryer and the expected duct size would also assist the reviewer in determining appropriate energy savings. Proposed Building: 1. Increase the dryer energy use by 20 percent based on a conservative rounding of the average results from Kao\'s study of dryer energy use. 20 percent is not necessarily a conservative figure. Further justification needs to be provided. Provide manufacturers data on the units and their proposed energy use. 2. Model the dryer such that all of the dryer energy results in heat gain in the space. Again, assuming that all of the energy used in the drying cycle results in heat gain to the space is not self evident. Industry accepted studies would be required to ensure that this is an acceptable assumption. 3. Model the proposed building without the dryer exhaust fans and without the additional 50 cfm of infiltration. This is acceptable as long as the figures determine from # 3 in the baseline case are used. Also, since the design team is proposing energy savings for the entire building based on the use of condensing dryers, some assurances must be given that all units will use condensing dryers." "None" "None" "LEED Interpretation" "5332" "2009-01-23" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "This question is in regards to a nursery and greenhouse project located in Golden Gate Park in San Francisco. Our project intends to use an EPA certified wood-fired gasification boiler as the main heating source for heating hot water (HHW): http://www.epa.gov/woodheaters/models.htm. This HHW will be used for both space heating in the nursery support building and for process loads in the greenhouse and may be used for DHW. The project will be managed by the Recreation and Parks Department, which oversees numerous parks throughout the city and has a readily available supply of wood from fallen trees at no cost except for the costs of wood transportation within the park and maintenance of the boiler. Because 1) EA credit 1 calculates the energy savings through usage and cost of conventional fuels, 2) EA credit 2 accepts biomass as an alternative and renewable energy source, and, 3) we do not have a method to quantify the cost of the fuel we are using, it is unclear how to accurately compare fuel usage. Our team is working off this assumption: The wood fuel for the gasification unit comes from standard tree maintenance and naturally occurring processes of tree life cycle and tree loss resulting from storms. Trees are not removed for commercial purposes and are therefore not defined as part of forestry practices, rather they are part of the Park\'s responsible stewardship of San Francisco\'s public resource and also address public safety. In addition, the wood supply is constantly regenerative, and the carbon emissions are the same as those produced during natural decomposition, and any other emissions are minimized in accordance to EPA standards. We believe this fuel source constitutes a renewable energy source. Our question is: Because the cost of heating water with wood gasification, as compared to a natural gas or propane system, is essentially zero, would it be accurate to exclude all energy costs associated with the gasification boiler?" "The applicant is asking a two-part question - 1) Since there is no cost associated with the wood is the heat free? 2) Can the applicant use the wood (as biomass) for renewable energy credits? 1) It appears that the applicant is attempting to compare a wood fired boiler with a natural gas and/or propane fire boiler. This assumption is not appropriate as ASHRAE 90.1-2004 prohibits fuel switching. If the applicant is proposing to use a wood fired boiler in the proposed case calculation, a wood fired boiler must be used in the ASHRAE case model. However, a different rate can be used in the baseline case. 2) The applicant can use the wood powered energy for renewable energy credits. The wood must be harvested from a site that is contiguous to the project site and has the same owner. Therefore this ruling is limited to Golden Gate Park, San Francisco." "10300" "None" "LEED Interpretation" "5342" "2009-02-09" "New Construction" "EAc1: Optimize Energy Performance" "Our project is a centralized beverage product distribution center consisting of an office area and an attached warehouse for storing carbonated beverages. The manufacturer has specified that product carbonation might be compromised if the space temperature were to rise above 90 deg. F. The facility is located in the Coachella Valley, California. While the area used to have a semi-desert climate, widespread agricultural irrigation has caused the humidity to increase in the area to the point that evaporative cooling is no longer an option. Since product quality is critical, the only way to maintain the maximum allowable temperature is to install a refrigeration system consisting of rooftop units. The unit controls will be locked out to provide cooling only to maintain a maximum of 90 degrees in the space; they are not designed (by virtue of their cooling capacity) to maintain human comfort temperatures in the space. The purpose of this Credit Interpretation Request is to clarify whether the power required to cool the warehouse to 90 degrees may be exempted from the process load simulation for EA Prerequisite 2 and Credit 1. The LEED NC Reference Guide states that, ""Appendix G of [ASHRAE] Standard 90.1-2004 requires that the energy analysis done for the Building Performance Rating Method include ALL of the energy costs within and associated with the building project."" However, the ASHRAE standard specifically refers to equipment within the conditioned space for human comfort. The ASHRAE Standard 90 User\'s Manual clarifies the standard intent in Section 5.3: ""The standard does not apply to equipment and portions of building systems that use energy primarily to provide for industrial, manufacturing or commercial processes. For example, the Standard does not apply to refrigerated warehouses that are cooled to maintain the quality of the goods stored in the warehouse."" In addition, the California Energy Code exempts spaces that are maintained above 90 degrees or below 55 degrees since they are outside of the comfort range. No standards, and therefore no baseline case for modeling refrigerated warehouses, currently exist. We have two questions: 1) Have we interpreted correctly that according to ASHRAE standard 90.1-2004, the energy related to the cooling system of the warehouse is exempt from the LEED EA Credit 1 simulation? If not, what baseline can we use? Please clarify. 2) If we exclude the energy from EA Credit 1, do we treat the other EA credits such as EA Credit 6 similarly?" "The applicant wants to exclude air-handlers that are used only to maintain 90F set point. It appears from the narrative that the use of air-handlers to maintain the 90F set point is a process requirement. While these air-handlers are exempt from ASHRAE 90.1-2004 and California Title 24, they have to be accounted for in the energy calculations for LEED. The energy consumed by these air-handlers must be maintained to be the same in both the proposed and the baseline models. These air-handlers must be accounted for in any calculations under EA credit 4 and EA credit 6." "2026, 2301, 5178" "None" "LEED Interpretation" "5344" "2009-04-15" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "The project undergoing the LEED process is an 847,218-sf warehouse with 22,776-sf of support offices in the same building. Eight (8) high-efficiency gas-fired rooftop units are proposed for providing heat to the warehouse space to maintain a 54-degree setpoint during the occupied hours of operation and a 50-degree setpoint during unoccupied hours (only heating provided to warehouse). The office area is proposed to be conditioned with high-efficiency gas-fired heating and DX cooling rooftop units serving separate interior and exterior spaces. The heating system for the warehouse is only designed to maintain setpoints intended to protect fire suppression sprinkler piping and other domestic piping systems from freezing during the winter. The heating and cooling system for the office area is designed to maintain temperature set points during the summer and winter for human comfort. The proposed control sequence for the warehouse rooftop units is to start the units two at a time with a dead-band of 3 degrees Fahrenheit - such that if the space temperature set point during winter is not maintained through the use of two units, two additional units will start, etc. The total heating output capacity of the eight (8) rooftop units proposed for the warehouse is higher than the heating load requirements for the purpose of safety and redundancy. The proposed rooftop units are direct-fired 80/20 units that also must be sized to maintain slight positive pressure when the overhead doors are closed. As per load calculations with Trace700 software, the warehouse falls under the semi-heated space category. As per total output capacity (of the direct-fired rooftop units sized for building pressurization), the warehouse falls under the conditioned space category. If we must consider the warehouse as a conditioned space, using Appendix-G of 90.1 performance rating method, the baseline case for both the warehouse and the office space is System #7: Variable Volume with Re-Heat, chilled water cooling and hot water boiler. The use of VAV system #7 as the baseline model for an energy modeling comparison is not reflective of a real-world system for a warehouse building. The proposed system for the warehouse that would need to be modeled in this case would be Constant Volume Rooftop Units with gas heat exchanger and chilled water coils. The proposed office system is Constant Volume Gas-fired Rooftop Units with DX cooling. The system type actually being proposed for this project is commonly used for all warehouses in this country. The energy savings that will be attained from our improved-efficiency of mechanical equipment, reduced lighting power density and improved building envelope performance will only be accurately reported if the proposed design is compared to a realistic baseline. Questions: 1. Can we consider the warehouse as a semi-heated space on the basis of heating requirements per peak load calculations and compare the baseline and proposed cases per the semi-heated space criteria? 2. The ASHRAE Standard 90.1-2004 page G-23 allows a building to be modeled with separate system types for separate occupancies (such as residential and non-residential). Can we treat warehouse and office spaces under separate occupancies and model these spaces with separate system types?" "The applicant is requesting a waiver from the requirement of modeling a conditioned space as per ASHRAE 90.1-2004. Please note: 1) A semi-heated space classification is based on the peak output of the equipment installed, and as described in the narrative, this space would not qualify. 2) Yes. If the office area is greater than 20,000 ft^2 of conditioned floor area, the project can be modeled as a separate system as per G3.1.1, exception (a) of ASHRAE 90.1-2004, Appendix G. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5350" "2009-07-16" "New Construction" "EAc1: Optimize Energy Performance" "Clarification is requested for energy modeling protocol on a lab building which is 44,000 sf in area. An energy model was done based on Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G. (http://www.epa.gov/lab21gov/pdf/ashrae_appg_draft_508.pdf). In previous CIRs (5/11/2005) earlier versions of these guidelines have been accepted in creating Baseline building models, except for calculating fan energies. Also, LEED for Laboratories Application Guide (Draft) states that the guideline may be used for energy modeling purposes. The project team, however, recently came across a CIR ruling dated 3/4/2008 that these guidelines may not be used. We would like to confirm: 1. If the Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G can be used to create the Baseline building model for our project? If not: 2. Per CIRs dated 11/3/2006 and 2/26/2007, the Baseline system should be representative of a typical system. Since Systems 3 & 4 (ASHRAE90.1 Table G3.1.1A) would not be suitable for a lab with 100% outside air requirements in Houston,TX, can we use System 5? 3. Per CIR dated 8/13/2007, can we use a min. flow ratio of 50% for our baseline-supply and baseline-exhaust, both? 4. Per CIRs dated 12/21/2004,2/4/2004,12/15/03(EAp2) fume hoods should be treated as process loads. In our project, it would be impossible to isolate the energy from these as they are synchronized with the supply VAV boxes, and are occupancy driven. In this context, they aid in modulating outdoor air levels and comfort ranges for occupants and hence cannot be treated as process loads. Can we let the fan energy associated with exhaust be part of overall ventilation energy? 5. Equipment power density for lab areas is taken at 8.0W/sf in both Proposed and Baseline models, referring to the typical value from Laboratories for the 21 Century:Energy Analysis. Is this acceptable?" "This CIR is asking several questions. The responses are: Question 1: No, the project may not use Labs21 to create the Baseline, as stated in the referenced CIR ruling dated 3/4/2008: ""Project teams may not use the Labs21 ""Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G"" as a compliance path for modeling laboratories. The deficiencies in modeling laboratories are being addressed through addenda to ASHRAE 90.1-2004. Project teams are permitted to use addenda to ASHRAE standards as outlined in a USGBC Memo posted here: http://www.usgbc.org/ShowFile.aspx?DocumentID=2664"". Question 2: The applicant is requesting a different system be used than the one prescribed by the ASHRAE Appendix G. As per the CIR rulings dated 11/3/2006 and 2/26/2007 that were referenced above, the system prescribed in Appendix G must be used as the baseline. It is unclear why System 3 or 4 would not be suitable for the lab building as mentioned in the CIR. Please note that the ASHRAE 90.1-2004 Standard Appendix G modeling protocol is not a compliance method but rather a method of comparing the proposed design\'s energy performance to a building that would have been typically built Question 3: The applicant is requesting clarification of minimum turndown ratios for the baseline system. The baseline laboratory exhaust only may be set as 50%, the supply and non laboratory exhaust systems must meet the requirements of Appendix G, as the referenced CIR dated 8/13/2007 states: Section 6.6.7.2 of Standard 90.1-2004 requires the proposed laboratory system to include either VAV controls that are capable of reducing exhaust and makeup air volume by 50% of design values or heat recovery meeting the requirements of Section 6.5.6.1. This is consistent with the applicants request to not include heat recovery in the baseline building model. In addition, the baseline VAV system serving the laboratory should only reduce the exhaust and makeup air volume to 50% of design values during unoccupied periods instead of the minimum volume setpoint of 0.4 cfm/ft2 of floor area as required by Section G3.1.3.13."" Question 4: The applicant is requesting clarification on how to account for fume hood operation. If the flow through the fume hoods is required to operate the building HVAC systems as designed, then they should be considered part of the HVAC system. If the fume hoods are operated in a way that is in addition to the required air-flow and ventilation air from the HVAC system, then they should be considered process loads. Question 5: The applicant is requesting acceptance of equipment power densities. Equipment power densities should be modeled in a way that best represents the designed equipment load in the building. If no more specific information is available for the project, the Labs21 baseline would seem to be a good guideline to use." "None" "None" "LEED Interpretation" "5356" "2009-07-20" "New Construction" "EAc1: Optimize Energy Performance" "In accordance with the Exceptional Calculation Method this CIR seeks confirmation of the approach indicated below in claiming energy savings on process loads. Project Description: This is a water reclamation project that takes water from a wastewater treatment plant and uses micro-filtration/ultra-filtration, reverse osmosis and finally ultraviolet radiation to treat the water. Many large motors drive pumps to move the water through the reclamation facility. The energy used by the pump motors represents greater than 90% of the energy used on the entire campus and represents the best opportunity for energy use reductions. Proposed Approach: The water treatment process runs nearly continuously throughout the year. Periodically, the membranes and filters that the water passes through get clogged, increasing the resistance that the pumps must overcome. Historically designs have used constant speed pumps to drive the water through the system coupled with resistance or bypass flow control devices to maintain constant flow volumes. It is proposed that constant speed motors be used as the basis for the baseline design. The proposed design would utilize variable frequency drives (VFD) to control the speed of the pumps to maintain flow through the system. The VFDs allow for running the pumps at lower speeds which results in lower energy use because percent of total power used at part speed is much less. Under normal conditions, when the membranes are clean, the motors will only need to operate at 80% of full speed. As the membranes begin to clog, the VFDs increase the pump speed to maintain constant flows. Please note that this baseline design and proposed design approach has been recognized and accepted (documentation can be provided) by Southern California Edison (local utility supplying power to the project) through their ""Savings By Design"" program. This program provides monetary incentive for projects that exceed the energy conservation requirements of California\'s Title 24 and the utility performs their own energy modeling to verify the designed savings. We seek confirmation that our proposed approach to claiming energy savings on the process loads is valid." "The project team is requesting that the project, a facility for water reclamation, be allowed to apply their energy savings from the installation of VFD\'s on the pumps operating the water reclamation system towards Energy and Atmosphere credit 1. The proposed exceptional calculation method approach described is acceptable; however documentation will need to be provided for certification. At a minimum, the applicant should provide: 1. Documentation verifying that constant flow pumping systems are an acceptable baseline or standard for water reclamation systems 2. Relevant sections of the Southern California Edison documentation referenced 3. A detailed narrative and back up data for how the baseline energy consumption was determined. 4. A detailed narrative describing the proposed processes taken credit for 5. Narratives and cutsheets of relevant equipment clearly highlighting the efficiency metric for each piece of equipment or drives credit is claimed for. The applicant should also note that if this project is process energy dominated, it will only qualify for a maximum of 4 points from the process energy efficiencies. *Please note (added 10/15/2009)*: Projects are now eligible to claim more than 4 points from process energy efficiency savings. This guidance supersedes CIR 2/9/2009 which placed 4 point maximum limit on process energy savings." "None" "None" "LEED Interpretation" "5358" "2009-09-02" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Station Lands - Phase 1 - EPCOR Tower: CIR for Energy and Atmosphere: Optimize Energy Performance (Credit 1) This CIR pertains to the appropriate Baseline system choice for a heated parkade, as per ASHRAE 90.1-2004. The building in question is a 29-storey office building with a 4-level underground parkade located in Climate Zone 7 (very cold, with \'5000-7000 annual heating degree days\'). The parkade is 26,500 sq.m. and requires 5,000 kW of heating capacity to heat the outdoor air (to ventilate the parkade) to above freezing point on the coldest day. The parkade will be heated to 4 \'degC\' in winter, and will not be cooled. In ASHRAE 90.1-2004, 189 W/sq.m. of heating output classifies this as a heated space according to Table 3.1 Heated Space Criteria, and the size of 26,500 sq.m. classifies it as requiring a System 7 - VAV w/ Reheat system in the Baseline according to Table G3.1.1A Baseline HVAC System Types. However, the parkade is a single thermal zone (earth on all walls and underneath, and a fully conditioned office space above), which makes a system choice of VAV seem inappropriate. The Proposed Design is a Built-up Single Zone system with natural gas furnace heat, and no cooling. Guidance from ASHRAE Technical personnel has been that ""the Baseline is to provide a simpler system than the Proposed design."" Question: In accordance with the actual thermal zoning of the parkade and the guideline that it is to be, generally, an equally simple or more simple system than the Proposed Design, should the Baseline system be a single zone system? If not, what is a proper system choice for the parkade in the Baseline case?" "Under Section 3, ""Definitions, Abbreviations, and Acronyms of ASHRAE Standard 90.1-2004 the definition of unconditioned space is as follows: an enclosed space within a building that is not a conditioned space or a semi-heated space. Crawlspaces, attics, and parking garages with natural or mechanical ventilation are not considered enclosed spaces."" The parkade equates to a parking garage and is not considered an enclosed space therefore there is no baseline system. Heating for the space should be modeled identically in both the proposed case and the baseline as process energy. An acceptable baseline would be another single zone natural gas furnace with the minimum efficiency prescribed by ASHRAE Standard 90.1-2004. You can claim energy savings for proposed case via Exceptional Calculation Methodology with all the required documentation. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5364" "2009-09-02" "New Construction, Schools - New Construction" "EAc1: Optimize Energy Performance" "This project is located in State College, Pennsylvania. The project involves a single greenhouse structure approximately 42ft by 108ft (4536 s.f.) for use by a Community Supported Agriculture (CSA) farm using sustainable and organic growing practices. Existing nearby facilities are able to serve as the only additional support space required leaving the greenhouse structure to serve as a single greenhouse space. Unlike the greenhouse identified in the CIR dated 1/8/2007, this project has no governing authority regarding energy conservation and the project\'s Authority Having Jurisdiction (AHJ) only governs this structure in regards to fire and life safety per the International Building Code (IBC) 2006 section 312.1. Therefore, we are requesting that the USGBC act as the AHJ for the greenhouse energy conservation requirements and ASHRAE 90.1 (2004) interpretations in effort to meet EAp2 of LEED v2.2. Per the ruling of the CIR submitted on 4/30/2008, the sole function of the building envelope is related to plant growth and therefore exempt from the prescriptive requirements of ASHRAE 90.1 (2004). However, unlike the greenhouse from the CIR dated 4/30/2008, this project does not involve additional spaces that are required to meet further requirements of the Standard. Therefore, no minimum requirements exist for the greenhouse building envelope for use in an energy model comparison in effort to achieve credits through EAcr1. In order to compare our proposed greenhouse design against a baseline, we are proposing the following approach: 1.) Since the amount of window used for the greenhouse impacts plant growth, we request that the greenhouse envelope be exempt from ASHRAE 90.1 (2004) item 5.5.4.2.1 and table G3.1.5 in regards to maximum window area permitted in the proposed design and model. We propose that both baseline and proposed design models have the same amount of window area without a limitation on the percent of gross wall area that can be modeled as window for the proposed design. 2.) We propose using the baseline window U-value of 0.98 from ASHRAE 90.1 (2004) table 5.5-5 for fixed vertical glazing in a semi-heated space equal to 40.1 to 50% of wall since this is the maximum percentage range provided and given the baseline window U-value permitted for CIR dated 1/8/2007. We request that the USGBC permit the space to be classified as semi-heated per ASHRAE 90.1 (2004) item 5.1.2.3 given that it is a process space not conditioned for human comfort. 3.) We propose to treat greenhouse lighting as unregulated lighting per ASHRAE 90.1 (2004) item 9.2.2.3 and the ruling for CIR submitted on 4/30/2008 and model the lighting identical in the baseline and proposed design models with the allowance to include daylighting controls in the proposed model only since it would result in additional energy savings and given it is above and beyond the bare minimum lighting system required for the growing process. 4.) We propose to use the minimum requirements for space heating of ASHRAE 90.1 (2004) in the baseline model in order to improve upon space heating energy efficiency in the proposed design in lieu of modeling space conditioning the same in the baseline and proposed design models as identified in the ruling for CIR submitted on 4/30/2008. For this application , we interpret ASHRAE 90.1 (2004) to prescribe an oil or gas-fired furnace with the prescribed minimum performance. Per AHRAE 90.1 (2004), all space conditioning setpoints and schedules shall remain the same between the baseline and proposed design models. Please confirm that this approach is acceptable." "The project is requesting guidance on creating the baseline energy model for a standalone greenhouse. The requested approach as detailed is acceptable. For certification, please provide a narrative describing the criteria for establishing your baseline and any applicable CIRs. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5376" "2009-07-20" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Project is an undergraduate teaching Science Center consisting of physics, chemistry and biology laboratories, class rooms and faculty offices. Project is to be designed to meet the standards and guidelines of US Army Corps of Engineers (USACE). Army requires EPACT compliance to be measured as a percentage reduction in energy use. Per USACE Army LEED Implementation (January 2008): Performance improvement is based on EPACT energy use reduction percentage (measured in Btu/SF) instead of energy cost reduction percentage (measured in kBtu/year, $/year). Percentage improvement (energy reduction percentage) is calculated as follows: oPercentage improvement = 100* (Base building consumption - Proposed building consumption) / (Base building consumption - Receptacle and Process loads) -USACE equation is different than the one used per LEED-NC v2.2. Per USACE compliance, Receptacle and Process loads are subtracted from the Base building energy consumption denominator. Receptacle and Process loads are included in the numerator. -Building consumption is based on kBtu/year. Compliance Path: Project uses Whole Building Energy Simulation (Option 1) method in conjunction with USACE EPACT energy use reduction percentage calculation to determine energy reduction for EAc1: Performance Rating Method-Alternative Compliance Points. Option 1-Whole Building Energy Simulation requires a percentage improvement in the proposed building performance rating compared to the baseline building performance rating per ASHRAE/IESNA Standard 90.1-2004 (without amendment) by a whole building project simulation using the Building Performance Rating Method in Appendix G of the Standard. From ASHRAE 90.1 Standard and Reference Guide for LEED-NC v2.2, the following items are related to this CIR request: Building performance is to include Receptacle and Process loads in both the numerator and the denominator for the Base Building Performance Performance improvement is based on energy cost savings in $/year Percentage improvement (energy cost reduction percentage) is calculated as follows: o Percentage improvement = 100 * (Baseline Building Performance - Proposed Building Performance) /(Baseline Building Performance) -Building performance is based on annual energy cost in $/year. Clarification requested: Please confirm that government project can be rated in accordance with USACE Army LEED Implementation (January 2008) guidelines and criteria for EAc1 credit - Performance Rating Method-Alternative Compliance Points based on the following: 1.Use energy consumption kBtu/year, not energy cost in $/year, to determine the Performance Improvement. 2.Use the USACE equation to calculate the percentage improvement and use this percentage improvement to determine the number of points for EAc1 - Alternate Compliance." "The project team requested an alternative compliance path for demonstrating energy savings that conforms to the US Army Corps of Engineers (USACE) LEED Implementation (January 2008) guidelines, in lieu of ASHRAE 90.1-2004 Appendix G - Performance Rating Method. Based on the description of the alternative compliance methodology, the approach is not an equivalent method for determining energy savings and is not acceptable. For consistency, projects pursuing compliance Option 1 must comply with ASHRAE 90.1-2004 section G1.1. Appendix G is a modified Energy Cost Budget method and energy savings must be accounted as a percentage of energy cost savings, as dictated in ASHRAE 90.1 Section G1.2. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5401" "2009-07-20" "New Construction, Schools - New Construction, Core and Shell" "EAc1: Optimize Energy Performance" "Our client is a Real Estate Investment Trust (REIT) that focuses on the development and ownership of grocery anchored retail centers. They own over 450 retail centers nationwide with over 60 million square feet of gross leasable area. They are interested in adopting a company-wide toolkit that provides consistency in their decision making process as it pertains to energy efficiency and overall sustainable/green strategies, including a minimum of LEED-CS2.0 certification. The main objective of this inquiry is related to the development of a methodology for earning EAc1 points, based upon a customized set of prescriptive energy efficiency measures determined through the energy modeling of five prototypes in eight climate regions that are demonstrated to effectively bring about minimum efficiencies to earn at least two EAc1 points. Currently, our client has developed five different prototype buildings that are distinct to each of the five markets/regions that they work in: Northeast, Southeast, Central, Southwest, and Northwest. Below is an outline of the modeling methodology and a description of the documentation that would be provided for certification review. We would like to propose the following prescriptive methodology for each prototype building, in lieu of performing individual energy modeling for each project seeking LEED certification under LEED-CS v2.0 rating system. If the approach is not acceptable, then we would like to receive guidance from the USGBC as to what aspects would need to be modified to obtain approval. Methodology: Develop a customized process and methodology for identifying the most appropriate energy saving strategies for all core & shell prototype projects. The approach is to use ASHRAE 90.1-2004 Appendix G modeling methodologies to investigate various energy efficiency measures for each of the five markets and prototypes and develop and compile a list of prescriptive building related measures that mirrors ASHRAE\'s Advanced Energy Design Guides (AEDG) Recommendation Table, but is customized to this developers specific project prototype approach. The intent is that only freestanding new construction core & shell buildings with individual HVAC systems are eligible. Projects that utilize energy supplied from district or centralized energy sources, e.g. district plant, would not be allowed to use this approach and must follow LEED guidance for projects using district supplied energy. Each market sector will be sub-categorized, as required, to correspond to one of ASHRAE\'s 8 climate zones. All prescriptive measures will be categorized to a prototype, a climate and to an orientation. The orientation will be determined by which way the building\'s main entryway is facing. All of the adopted prescriptive measures will be generated and evaluated using eQuest DOE2 energy modeling software. The software exceeds ASHRAE Appendix G minimum simulation software criteria. For consistency, the building\'s prescriptive measures will be grouped to correspond similarly with ASHRAE\'s AEDG structure. Below is an outline of how the building components with be grouped and categorized:  Envelope: Roof, Walls, Floors, Slabs, Doors, Vertical Glazing, and Skylights  Lighting: Interior and Exterior Lighting  HVAC: HVAC, Economizer, Ventilation, Ducts  Service Hot Water: Service Hot Water Heater LEED Submission: The documentation that would be provided to USGBC for LEED certification review would consist of the following:  A signed LEED Submittal Template declaring an alternative compliance path has been followed.  A copy of a CIR or other documentation from the USGBC approving the alternative compliance path.  A narrative describing the modeling methods and supporting that they conform to ASHRAE 90.1-2004  A comparison summary table demonstrating that the energy measures implemented in the project correspond with the required prescriptive measures.  Any additional documentation necessary to support the claimed energy savings. This customized approach for EAc1 will result in meeting both the intent and the performance requirements of the credit. Can we proceed with this approach and if not, how would we need to modify this approach to be acceptable to the USGBC?" "The project team is requesting that five standard energy models based on a design \'prototype\' from five different regions be acceptable documentation for all prototype projects from that owner/developer currently pursuing LEED certification in lieu of creating energy models for each project in line with the requirements for EA Credit 1. Each individual project will have energy use/cost variations depending on objects other region and system type. Energy use and cost is greatly impacted by: building orientation, elevation, average solar gain, utility rates, local code requirements, and more. A snapshot prototype energy model will not adequately describe the energy requirements of all projects in the same region, and an individual energy model must be submitted for each building pursuing certification. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5489" "2008-10-03" "New Construction" "EAc1: Optimize Energy Performance" "Background The Phoenix Sky Harbor International Airport Automated Train project consists of an automated electric train which travels on an open, elevated railway serving three train stations. One station is attached to the existing air terminal building #4, one makes connection to the municipal light rail station adjacent to the airport at 44th Street, and the third (the EEL Station) is located on the rail system part way between these stations and adjacent to an existing parking garage. The terminal #4 and 44th St. stations are enclosed and conditioned and the application of LEED criteria is fairly straightforward. It has been suggested by value engineering that the EEL station be constructed as an ""open"" or unenclosed, unconditioned structure with a roof and interior lighting, but no exterior walls. The station will include normally unoccupied, enclosed, and conditioned ancillary equipment rooms which house electrical and communications/security equipment. It is anticipated that these ancillary areas will constitute about 5% of the total building area. Credit Interpretation Request This question deals with how the unconditioned, unenclosed portions of this building can evidence compliance with EA prerequisites and credits. In researching past CIRs on the USGBC website several cases involving unconditioned buildings were found, but none matched our project sufficiently to provide a level of confidence in the interpretation of requirements. In the proposed design, the unconditioned, unenclosed portions of the building will be naturally ventilated with no HVAC equipment, while the enclosed ancillary equipment spaces will be conditioned with conventional A/C or evaporative cooling and electric heating equipment. It is desired that the entire building be considered for certification, not just the ancillary areas. In configuration, this building most resembles a parking garage where there is lighting, vertical transportation, and conditioned ancillary areas, but no conditioning or enclosure of the occupied areas. The LEED NC Version 2.2 Reference Guide (First Edition) indicates on page 181 under HVAC system types that ""For areas of the project without heating or cooling systems (such as parking garages), there is no need to model heating or cooling systems in either the Proposed or Baseline designs. This was supported by the CIR ruling dated 1/29/2008 relating to a CIR submitted on 1/11/2008 that addressed energy use simulation of unconditioned buildings. The Ruling stated ""For EAc1, these buildings would be treated very similarly to unconditioned parking garages, where the envelope does not necessarily need to be modeled, but the electric loads from the lighting and fans are included in the energy calculations."" Will it be permitted to treat the EEL station in this fashion, where the energy simulation will include use by lighting, vertical transportation and other ancillary energy uses, but not HVAC systems in the unenclosed areas? The HVAC systems serving conditioned equipment rooms will be included in the simulation and their performance will be compared with the baseline systems specified by ASHRAE Std 90.1 - 2004, Appendix G. Since the envelope requirements of ASHRAE 90.1 - 2004 do not apply to unenclosed and unconditioned buildings, may we assume that EAp2 is automatically satisfied for the unconditioned portions of the buildings and only the conditioned, ancillary portions of the building must comply?" "The project team is requesting guidance on modeling an unenclosed structure under EAc1 - Whole Building Simulation, and how to satisfy EAp2 for the same building. For the unenclosed portions, the project team may follow the instruction given in the cited CIR (dated 1/29/2008); treating the unenclosed portion similarly to an unenclosed parking garage. The enclosed portions should be modeled as conditioned and adhere to the ASHRAE 90.1-2004 standard Appendix G modeling guidelines. For EAp2, as stated in the referenced CIR, the applicable minimum requirements of ASHRAE 90.1-2004 must be met under EAp2. This holds true for both the unenclosed and enclosed portions of the structure. The project must also include occupied interior space in order to be eligible for certification. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5808" "2009-02-09" "New Construction" "EAc1: Optimize Energy Performance" "null" "Please refer to LEED Interpretation 2475" "None" "None" "LEED Interpretation" "873" "2004-11-01" "New Construction" "EAc1: Optimize Energy Performance" "Our team has a unique opportunity to utilize the project\'s roof snowmelt system during non-snowmelt sunny days to preheat domestic hot water. This heat recovery system would operate similar to a conventional solar thermal panel system minimizing consumption of fossil fuels. The copper roof, when not covered in snow, would absorb the solar energy, heating the coils, which we\'d then use to pre-heat domestic water. We are not aware of this being done before. In addition, we anticipate running calculations after construction to calculate energy savings data. Will the USGBC grant an Innovation and Design credit for this unique system? Also, will the USGBC grant Optimize Energy Performance and Renewable Energy credits if the system satisfies the credit requirements?" "NOTE: This ruling has been overturned by an administrative EAc2.1 ruling dated 7/7/2006 which updates the definition of qualifying renewable energy. The use of solar thermal technology is a strategy that qualifies for energy savings under EAc1: Optimize Energy Performance. Innovation credits are not awarded if the strategy contributes to an existing credit, such as with this case. EAc2 (Renewable Energy) is based on renewable strategies which generate electricity. The LEED-NC v2.1 Reference Guide specifically states on page 155 that solar hot water heating is not applicable to EAc2. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "10277" "2013-04-01" "New Construction, Schools - New Construction, Retail - New Construction, Healthcare" "EAc1: Optimize Energy Performance" "The purpose of this inquiry is to determine if our approach for energy modeling required by credits EAc1 and EAc5 is acceptable. Our project is a 215,800 square foot patient room and administration office addition to an existing hospital. The LEED boundary for the LEED certification includes the new addition only. A boiler and chiller plant provides heating and cooling to the existing hospital and is located within the existing building. The boiler and chiller plant equipment will be demolished and a new, larger boiler and chiller plant will be built within the new attached addition, and will serve both the new addition and existing hospital. The new building addition within the LEED boundary will be served by its own air handling units with hot- and chilled- water coils served from the new mechanical plant which is also within the LEED boundary. We would like to confirm that the following approaches are acceptable: 1) Exclude the existing building which is outside of the LEED boundary from the energy models; and 2) Model the new addition in the budget and proposed design models with a mechanical plant that is appropriately sized for the addition only, and use in the models the efficiencies of the plant equipment that is sized to serve the entire hospital. The equipment sized for the new addition only is in the same size category referenced in ASHRAE 90.1 Section 6 as equipment sized to serve the entire building, so the efficiencies would be the same. " """The proposed modeling approach of sizing the plants within the model for the new addition only is not acceptable. However, since the new mechanical plant located within the LEED Project Boundary is intended to serve both the LEED project building and the remaining existing portion of the building, the plant would effectively be a district thermal energy plant. Therefore, the project team is encouraged to utilize the Treatment of District or Campus Thermal Energy in LEED v2 and LEED 2009 Design & Construction (DESv2.0). \n Per the DES guidance, the proposed building heating and cooling are to be modeled using a virtual plant, with average efficiencies that are determined using either the monitoring or modeling methods described in Appendix C. Note that the DES Guidance indicates that when the building housing the thermal energy plant is itself seeking LEED certification, then the project shall treat the DES equipment as downstream equipment for certain prerequisites and credits (including commissioning credits: EAp1 & EAc3, refrigerant credits: EAp3 & EAc4, and measurement and verification: EAc5). However, for the energy model, the district energy equipment shall be modeled as upstream equipment, and the project is recommended to use modeling Option 2, which is allowed even if the minimum point floor from Table 1 is not reached for the project. Although the existing portion of the building does not have to be modeled explicitly, some form of modeling of the district plant and the total load from all buildings (or portions of the building) anticipated to be connected to that plant is required in order to calculate the average efficiency. Generally, some form of load calculation, and identification of predicted load profiles is used when sizing a central plant, and identifying the central plant equipment that will be installed. This data can be used to develop a simple central plant energy model, where the loads from all of the buildings are modeled using the combination of a process load on the plant and a schedule. As stated in Appendix C, average efficiencies may be determined annually, seasonally, monthly, hourly, or for each utility block, as long as the same time scale and method used (either monitoring or modeling) to derive the average efficiency for heating or cooling is consistent for all related district thermal systems that are part of the LEED project. Please note that this means the schedules modeled for this plant model may be as complex as hourly schedules with predicted variations for each hour of the year, or as simple as an annual average load on the district plant assumed for the whole time the plant is anticipated to be operating on an annual basis. For EA Credit 5: Measurement and Verification, clarification should be provided to identify how the energy loads (including thermal loads) for the new addition will be metered separately from the energy loads for the existing building.
Note: This interpretation ruling does not address whether the building addition qualifies with the (Guidance for Certifying Attached Buildings Separately) which is also contained in Version 2 of the LEED 2009 MPR Supplemental Guidance Document.” \n Applicable Internationally."" " "5496" "LEED-NC Application Guide for Multiple Buildings and On-Campus Building Projects, LEED 2009 MPR Supplemental Guidance revision 2 (September 2011), Attached Buildings Guidance" "X" "X" "LEED Interpretation" "10286" "2013-10-01" "New Construction, Core and Shell, Schools - New Construction, Retail - New Construction, Healthcare" "A centrifugal chiller, manufactured in Brazil, is specified for the project. The chiller is not AHRI certified and there is no laboratory in Brazil that can do this test. Since there is no laboratory in Brazil that can do this test, to comply with section 6.4.1.4 Verification of Equipment Efficiencies of ASHRAE 90.1-2007 Standard, would the equipment fall under option d (if no certification program exists for a covered product, the equipment efficiency ratings shall be supported by data furnished by the manufacturer)? Can this equipment be used in the project?" "A supplier’s claims regarding energy efficiency would not be considered sufficient to document compliance with EA Prerequisite 2 (Minimum Energy Performance) and EA Credit 1 (Optimize Energy Performance) for a centrifugal HVAC unit that has not been tested and certified by a 3rd party in accordance with AHRI Standard 550-590. However, if the project team can provide documentation that the efficiency has been tested by a third party using an equivalent standard for HVAC efficiency, this testing would be sufficient in lieu of the AHRI Standard 550-990 testing. Any differences in test conditions and the resulting adjustments to the efficiency values claimed in the energy model would need to be described in the project submittal documentation. Alternatively, the project team may use the supplier’s claims regarding energy efficiency if the commissioning scope of work includes field testing of the equipment efficiency for the range of full- and part-load design conditions under which the building will operate; any adjustments related to altitude, etc. must be accounted for in the commissioning testing. In this case, the energy modeling documentation must include details about the commissioning functional testing method to confirm the performance of the chiller at full and part load operation. If the LEED submittal is provided as a split design / construction phase submittal, and the commissioning agent determines that the equipment efficiency does not meet or exceed the efficiency values claimed by the supplier, the energy documentation must be resubmitted at the construction phase with the values measured by the commissioning agent." "None" "None" "X" "Brazil" "LEED Interpretation" "10390" "2014-07-01" "New Construction, Core and Shell, Schools - New Construction, Retail - New Construction, Healthcare, Commercial Interiors, Retail - Commercial Interiors" "EAp2:Minimum Energy Performance" "There is significant confusion, and seemingly contradictory LEED Interpretations on the required methodology for addressing “purchased” on-site renewable energy, and/or purchased biofuel that is not considered on-site renewable energy within the LEED energy model. For renewable fuels meeting the requirements of Addendum 100001081 (November 1, 2011) or other purchased renewable fuels, how should purchased on-site renewable energy be treated in the LEED energy model? How should purchased bio-fuels (meaning it I not fossil fuel but is used in a similar manner to bio-fuel) be treated in the energy model?" "For any on-site renewable fuel source that is purchased (such as qualifying wood pellets, etc.), or for biofuels not qualifying as on-site renewable fuel sources that are purchased, the actual energy costs associated with the purchased energy must be modeled in EA Prerequisite 2: Minimum Energy Performance and EA Credit 1: Optimize Energy Performance, and the renewable fuel source may not be modeled as ""free"", since it is a purchased energy source.\n\n For non-traditional fuel sources (such as wood pellets) that are unregulated within ASHRAE 90.1, use the actual cost of the fuel, and provide documentation to substantiate the cost for the non-traditional fuel source. The same rates are to be used for the baseline and proposed buildings, with the following exception: If the fuel source is available at a discounted cost because it would otherwise be sent to the landfill or similarly disposed of, the project team may use local rates for the fuel for the baseline case and actual rates for the proposed case, as long as documentation is provided substantiating the difference in rates, and substantiating that the fuel source would otherwise be disposed of.\n\n When these non-traditional fuel sources are used for heating the building, the proposed case heating source must be the same as the baseline case for systems using the non-traditional fuel source, and the project team must use fossil fuel efficiencies for the Baseline systems, or provide evidence justifying that the baseline efficiencies represent standard practice for a similar, newly constructed project with the same fuel source." "100001081" "None" "X" "X"